Index: README.md
==================================================================
--- README.md
+++ README.md
@@ -21,7 +21,6 @@
 
 The software, including the manual, is licensed
 under the [European Union Public License 1.2 (or
 later)](https://zettelstore.de/home/file?name=LICENSE.txt&ci=trunk).
 
-[Stay](https://twitter.com/zettelstore)
-<a rel="me" href="https://nerdculture.de/@zettelstore">tuned</a>&nbsp;&hellip;
+[Stay tuned](https://twitter.com/search?q=%40t73fde%20zettelstore&f=live)&nbsp;&hellip;

Index: VERSION
==================================================================
--- VERSION
+++ VERSION
@@ -1,1 +1,1 @@
-0.11.0
+0.12-dev

Index: ast/ast.go
==================================================================
--- ast/ast.go
+++ ast/ast.go
@@ -12,20 +12,20 @@
 package ast
 
 import (
 	"net/url"
 
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // ZettelNode is the root node of the abstract syntax tree.
 // It is *not* part of the visitor pattern.
 type ZettelNode struct {
 	Meta    *meta.Meta     // Original metadata
-	Content domain.Content // Original content
+	Content zettel.Content // Original content
 	Zid     id.Zid         // Zettel identification.
 	InhMeta *meta.Meta     // Metadata of the zettel, with inherited values.
 	Ast     BlockSlice     // Zettel abstract syntax tree is a sequence of block nodes.
 	Syntax  string         // Syntax / parser that produced the Ast
 }

Index: ast/ref.go
==================================================================
--- ast/ref.go
+++ ast/ref.go
@@ -12,11 +12,11 @@
 
 import (
 	"net/url"
 	"strings"
 
-	"zettelstore.de/z/domain/id"
+	"zettelstore.de/z/zettel/id"
 )
 
 // QueryPrefix is the prefix that denotes a query expression.
 const QueryPrefix = "query:"
 

Index: auth/auth.go
==================================================================
--- auth/auth.go
+++ auth/auth.go
@@ -14,12 +14,12 @@
 import (
 	"time"
 
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // BaseManager allows to check some base auth modes.
 type BaseManager interface {
 	// IsReadonly returns true, if the systems is configured to run in read-only-mode.
@@ -40,12 +40,12 @@
 type TokenKind int
 
 // Allowed values of token kind
 const (
 	_ TokenKind = iota
-	KindJSON
-	KindHTML
+	KindAPI
+	KindwebUI
 )
 
 // TokenData contains some important elements from a token.
 type TokenData struct {
 	Token   []byte

Index: auth/cred/cred.go
==================================================================
--- auth/cred/cred.go
+++ auth/cred/cred.go
@@ -13,11 +13,11 @@
 
 import (
 	"bytes"
 
 	"golang.org/x/crypto/bcrypt"
-	"zettelstore.de/z/domain/id"
+	"zettelstore.de/z/zettel/id"
 )
 
 // HashCredential returns a hashed vesion of the given credential
 func HashCredential(zid id.Zid, ident, credential string) (string, error) {
 	fullCredential := createFullCredential(zid, ident, credential)

Index: auth/impl/impl.go
==================================================================
--- auth/impl/impl.go
+++ auth/impl/impl.go
@@ -22,13 +22,13 @@
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/auth/policy"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type myAuth struct {
 	readonly bool
 	owner    id.Zid

Index: auth/policy/anon.go
==================================================================
--- auth/policy/anon.go
+++ auth/policy/anon.go
@@ -11,11 +11,11 @@
 package policy
 
 import (
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type anonPolicy struct {
 	authConfig config.AuthConfig
 	pre        auth.Policy

Index: auth/policy/box.go
==================================================================
--- auth/policy/box.go
+++ auth/policy/box.go
@@ -14,15 +14,15 @@
 	"context"
 
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/query"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // BoxWithPolicy wraps the given box inside a policy box.
 func BoxWithPolicy(
 	manager auth.AuthzManager,
@@ -53,31 +53,31 @@
 
 func (pp *polBox) CanCreateZettel(ctx context.Context) bool {
 	return pp.box.CanCreateZettel(ctx)
 }
 
-func (pp *polBox) CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
+func (pp *polBox) CreateZettel(ctx context.Context, zettel zettel.Zettel) (id.Zid, error) {
 	user := server.GetUser(ctx)
 	if pp.policy.CanCreate(user, zettel.Meta) {
 		return pp.box.CreateZettel(ctx, zettel)
 	}
 	return id.Invalid, box.NewErrNotAllowed("Create", user, id.Invalid)
 }
 
-func (pp *polBox) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
-	zettel, err := pp.box.GetZettel(ctx, zid)
+func (pp *polBox) GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error) {
+	z, err := pp.box.GetZettel(ctx, zid)
 	if err != nil {
-		return domain.Zettel{}, err
+		return zettel.Zettel{}, err
 	}
 	user := server.GetUser(ctx)
-	if pp.policy.CanRead(user, zettel.Meta) {
-		return zettel, nil
+	if pp.policy.CanRead(user, z.Meta) {
+		return z, nil
 	}
-	return domain.Zettel{}, box.NewErrNotAllowed("GetZettel", user, zid)
+	return zettel.Zettel{}, box.NewErrNotAllowed("GetZettel", user, zid)
 }
 
-func (pp *polBox) GetAllZettel(ctx context.Context, zid id.Zid) ([]domain.Zettel, error) {
+func (pp *polBox) GetAllZettel(ctx context.Context, zid id.Zid) ([]zettel.Zettel, error) {
 	return pp.box.GetAllZettel(ctx, zid)
 }
 
 func (pp *polBox) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
 	m, err := pp.box.GetMeta(ctx, zid)
@@ -104,15 +104,15 @@
 	canRead := pp.policy.CanRead
 	q = q.SetPreMatch(func(m *meta.Meta) bool { return canRead(user, m) })
 	return pp.box.SelectMeta(ctx, q)
 }
 
-func (pp *polBox) CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool {
+func (pp *polBox) CanUpdateZettel(ctx context.Context, zettel zettel.Zettel) bool {
 	return pp.box.CanUpdateZettel(ctx, zettel)
 }
 
-func (pp *polBox) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
+func (pp *polBox) UpdateZettel(ctx context.Context, zettel zettel.Zettel) error {
 	zid := zettel.Meta.Zid
 	user := server.GetUser(ctx)
 	if !zid.IsValid() {
 		return &box.ErrInvalidID{Zid: zid}
 	}

Index: auth/policy/default.go
==================================================================
--- auth/policy/default.go
+++ auth/policy/default.go
@@ -11,11 +11,11 @@
 package policy
 
 import (
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/auth"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type defaultPolicy struct {
 	manager auth.AuthzManager
 }

Index: auth/policy/owner.go
==================================================================
--- auth/policy/owner.go
+++ auth/policy/owner.go
@@ -12,11 +12,11 @@
 
 import (
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type ownerPolicy struct {
 	manager    auth.AuthzManager
 	authConfig config.AuthConfig

Index: auth/policy/policy.go
==================================================================
--- auth/policy/policy.go
+++ auth/policy/policy.go
@@ -12,11 +12,11 @@
 package policy
 
 import (
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // newPolicy creates a policy based on given constraints.
 func newPolicy(manager auth.AuthzManager, authConfig config.AuthConfig) auth.Policy {
 	var pol auth.Policy

Index: auth/policy/policy_test.go
==================================================================
--- auth/policy/policy_test.go
+++ auth/policy/policy_test.go
@@ -14,12 +14,12 @@
 	"fmt"
 	"testing"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/auth"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func TestPolicies(t *testing.T) {
 	t.Parallel()
 	testScene := []struct {

Index: auth/policy/readonly.go
==================================================================
--- auth/policy/readonly.go
+++ auth/policy/readonly.go
@@ -8,15 +8,15 @@
 // under this license.
 //-----------------------------------------------------------------------------
 
 package policy
 
-import "zettelstore.de/z/domain/meta"
+import "zettelstore.de/z/zettel/meta"
 
 type roPolicy struct{}
 
 func (*roPolicy) CanCreate(_, _ *meta.Meta) bool   { return false }
 func (*roPolicy) CanRead(_, _ *meta.Meta) bool     { return true }
 func (*roPolicy) CanWrite(_, _, _ *meta.Meta) bool { return false }
 func (*roPolicy) CanRename(_, _ *meta.Meta) bool   { return false }
 func (*roPolicy) CanDelete(_, _ *meta.Meta) bool   { return false }
 func (*roPolicy) CanRefresh(user *meta.Meta) bool  { return user != nil }

Index: box/box.go
==================================================================
--- box/box.go
+++ box/box.go
@@ -17,14 +17,14 @@
 	"fmt"
 	"io"
 	"time"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // BaseBox is implemented by all Zettel boxes.
 type BaseBox interface {
 	// Location returns some information where the box is located.
@@ -34,23 +34,23 @@
 	// CanCreateZettel returns true, if box could possibly create a new zettel.
 	CanCreateZettel(ctx context.Context) bool
 
 	// CreateZettel creates a new zettel.
 	// Returns the new zettel id (and an error indication).
-	CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error)
+	CreateZettel(ctx context.Context, zettel zettel.Zettel) (id.Zid, error)
 
 	// GetZettel retrieves a specific zettel.
-	GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error)
+	GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error)
 
 	// GetMeta retrieves just the meta data of a specific zettel.
 	GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error)
 
 	// CanUpdateZettel returns true, if box could possibly update the given zettel.
-	CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool
+	CanUpdateZettel(ctx context.Context, zettel zettel.Zettel) bool
 
 	// UpdateZettel updates an existing zettel.
-	UpdateZettel(ctx context.Context, zettel domain.Zettel) error
+	UpdateZettel(ctx context.Context, zettel zettel.Zettel) error
 
 	// AllowRenameZettel returns true, if box will not disallow renaming the zettel.
 	AllowRenameZettel(ctx context.Context, zid id.Zid) bool
 
 	// RenameZettel changes the current Zid to a new Zid.
@@ -135,11 +135,11 @@
 
 	// SelectMeta returns a list of metadata that comply to the given selection criteria.
 	SelectMeta(ctx context.Context, q *query.Query) ([]*meta.Meta, error)
 
 	// GetAllZettel retrieves a specific zettel from all managed boxes.
-	GetAllZettel(ctx context.Context, zid id.Zid) ([]domain.Zettel, error)
+	GetAllZettel(ctx context.Context, zid id.Zid) ([]zettel.Zettel, error)
 
 	// GetAllMeta retrieves the meta data of a specific zettel from all managed boxes.
 	GetAllMeta(ctx context.Context, zid id.Zid) ([]*meta.Meta, error)
 
 	// Refresh the data from the box and from its managed sub-boxes.

Index: box/compbox/compbox.go
==================================================================
--- box/compbox/compbox.go
+++ box/compbox/compbox.go
@@ -16,16 +16,16 @@
 	"net/url"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/box/manager"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	manager.Register(
 		" comp",
@@ -70,32 +70,32 @@
 
 func (*compBox) Location() string { return "" }
 
 func (*compBox) CanCreateZettel(context.Context) bool { return false }
 
-func (cb *compBox) CreateZettel(context.Context, domain.Zettel) (id.Zid, error) {
+func (cb *compBox) CreateZettel(context.Context, zettel.Zettel) (id.Zid, error) {
 	cb.log.Trace().Err(box.ErrReadOnly).Msg("CreateZettel")
 	return id.Invalid, box.ErrReadOnly
 }
 
-func (cb *compBox) GetZettel(_ context.Context, zid id.Zid) (domain.Zettel, error) {
+func (cb *compBox) GetZettel(_ context.Context, zid id.Zid) (zettel.Zettel, error) {
 	if gen, ok := myZettel[zid]; ok && gen.meta != nil {
 		if m := gen.meta(zid); m != nil {
 			updateMeta(m)
 			if genContent := gen.content; genContent != nil {
 				cb.log.Trace().Msg("GetMeta/Content")
-				return domain.Zettel{
+				return zettel.Zettel{
 					Meta:    m,
-					Content: domain.NewContent(genContent(m)),
+					Content: zettel.NewContent(genContent(m)),
 				}, nil
 			}
 			cb.log.Trace().Msg("GetMeta/NoContent")
-			return domain.Zettel{Meta: m}, nil
+			return zettel.Zettel{Meta: m}, nil
 		}
 	}
 	cb.log.Trace().Err(box.ErrNotFound).Msg("GetZettel/Err")
-	return domain.Zettel{}, box.ErrNotFound
+	return zettel.Zettel{}, box.ErrNotFound
 }
 
 func (cb *compBox) GetMeta(_ context.Context, zid id.Zid) (*meta.Meta, error) {
 	if gen, ok := myZettel[zid]; ok {
 		if genMeta := gen.meta; genMeta != nil {
@@ -140,13 +140,13 @@
 		}
 	}
 	return nil
 }
 
-func (*compBox) CanUpdateZettel(context.Context, domain.Zettel) bool { return false }
+func (*compBox) CanUpdateZettel(context.Context, zettel.Zettel) bool { return false }
 
-func (cb *compBox) UpdateZettel(context.Context, domain.Zettel) error {
+func (cb *compBox) UpdateZettel(context.Context, zettel.Zettel) error {
 	cb.log.Trace().Err(box.ErrReadOnly).Msg("UpdateZettel")
 	return box.ErrReadOnly
 }
 
 func (*compBox) AllowRenameZettel(_ context.Context, zid id.Zid) bool {

Index: box/compbox/config.go
==================================================================
--- box/compbox/config.go
+++ box/compbox/config.go
@@ -12,13 +12,13 @@
 
 import (
 	"bytes"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func genConfigZettelM(zid id.Zid) *meta.Meta {
 	if myConfig == nil {
 		return nil

Index: box/compbox/keys.go
==================================================================
--- box/compbox/keys.go
+++ box/compbox/keys.go
@@ -13,13 +13,13 @@
 import (
 	"bytes"
 	"fmt"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func genKeysM(zid id.Zid) *meta.Meta {
 	m := meta.New(zid)
 	m.Set(api.KeyTitle, "Zettelstore Supported Metadata Keys")

Index: box/compbox/log.go
==================================================================
--- box/compbox/log.go
+++ box/compbox/log.go
@@ -12,13 +12,13 @@
 
 import (
 	"bytes"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func genLogM(zid id.Zid) *meta.Meta {
 	m := meta.New(zid)
 	m.Set(api.KeyTitle, "Zettelstore Log")

Index: box/compbox/manager.go
==================================================================
--- box/compbox/manager.go
+++ box/compbox/manager.go
@@ -13,13 +13,13 @@
 import (
 	"bytes"
 	"fmt"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func genManagerM(zid id.Zid) *meta.Meta {
 	m := meta.New(zid)
 	m.Set(api.KeyTitle, "Zettelstore Box Manager")

Index: box/compbox/parser.go
==================================================================
--- box/compbox/parser.go
+++ box/compbox/parser.go
@@ -15,14 +15,14 @@
 	"fmt"
 	"sort"
 	"strings"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func genParserM(zid id.Zid) *meta.Meta {
 	m := meta.New(zid)
 	m.Set(api.KeyTitle, "Zettelstore Supported Parser")

Index: box/compbox/version.go
==================================================================
--- box/compbox/version.go
+++ box/compbox/version.go
@@ -10,13 +10,13 @@
 
 package compbox
 
 import (
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func getVersionMeta(zid id.Zid, title string) *meta.Meta {
 	m := meta.New(zid)
 	m.Set(api.KeyTitle, title)

Index: box/constbox/base.mustache
==================================================================
--- box/constbox/base.mustache
+++ box/constbox/base.mustache
@@ -12,28 +12,24 @@
 <title>{{Title}}</title>
 </head>
 <body>
 <nav class="zs-menu">
 <a href="{{{HomeURL}}}">Home</a>
-{{#WithUser}}
+{{#WithAuth}}
 <div class="zs-dropdown">
 <button>User</button>
 <nav class="zs-dropdown-content">
-{{#WithAuth}}
 {{#UserIsValid}}
 <a href="{{{UserZettelURL}}}">{{UserIdent}}</a>
+<a href="{{{LogoutURL}}}">Logout</a>
 {{/UserIsValid}}
 {{^UserIsValid}}
 <a href="{{{LoginURL}}}">Login</a>
 {{/UserIsValid}}
-{{#UserIsValid}}
-<a href="{{{LogoutURL}}}">Logout</a>
-{{/UserIsValid}}
-{{/WithAuth}}
 </nav>
 </div>
-{{/WithUser}}
+{{/WithAuth}}
 <div class="zs-dropdown">
 <button>Lists</button>
 <nav class="zs-dropdown-content">
 <a href="{{{ListZettelURL}}}">List Zettel</a>
 <a href="{{{ListRolesURL}}}">List Roles</a>

ADDED   box/constbox/base.sxn
Index: box/constbox/base.sxn
==================================================================
--- box/constbox/base.sxn
+++ box/constbox/base.sxn
@@ -0,0 +1,48 @@
+(@@@@
+(html ,@(if lang `((@ (lang ,lang))))
+(head
+  (meta (@ (charset "utf-8")))
+  (meta (@ (name "viewport") (content "width=device-width, initial-scale=1.0")))
+  (meta (@ (name "generator") (content "Zettelstore")))
+  (meta (@ (name "format-detection") (content "telephone=no")))
+  ,@META-HEADER
+  (link (@ (rel "stylesheet") (href ,css-base-url)))
+  (link (@ (rel "stylesheet") (href ,css-user-url)))
+  ,@(if css-role-url `((link (@ (rel "stylesheet") (href ,css-role-url)))))
+  (title ,title))
+(body
+  (nav (@ (class "zs-menu"))
+    (a (@ (href ,home-url)) "Home")
+    ,@(if with-auth
+      `((div (@ (class "zs-dropdown"))
+        (button "User")
+        (nav (@ (class "zs-dropdown-content"))
+          ,@(if user-is-valid
+            `((a (@ (href ,user-zettel-url)) ,user-ident)
+              (a (@ (href ,logout-url)) "Logout"))
+            `((a (@ (href ,login-url)) "Login"))
+          )
+      )))
+    )
+    (div (@ (class "zs-dropdown"))
+      (button "Lists")
+      (nav (@ (class "zs-dropdown-content"))
+        (a (@ (href ,list-zettel-url)) "List Zettel")
+        (a (@ (href ,list-roles-url)) "List Roles")
+        (a (@ (href ,list-tags-url)) "List Tags")
+        ,@(if can-refresh `((a (@ (href ,refresh-url)) "Refresh")))
+    ))
+    ,@(if new-zettel-links
+      `((div (@ (class "zs-dropdown"))
+        (button "New")
+        (nav (@ (class "zs-dropdown-content"))
+          ,@(map pair-to-href new-zettel-links)
+       )))
+    )
+    (form (@ (action ,search-url))
+      (input (@ (type "text") (placeholder "Search..") (name ,query-key-query))))
+  )
+  (main (@ (class "content")) ,DETAIL)
+  ,@(if FOOTER `((footer (hr) ,@FOOTER)))
+  ,@(if debug-mode '((div (b "WARNING: Debug mode is enabled. DO NOT USE IN PRODUCTION!"))))
+)))

Index: box/constbox/constbox.go
==================================================================
--- box/constbox/constbox.go
+++ box/constbox/constbox.go
@@ -17,16 +17,16 @@
 	"net/url"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/box/manager"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	manager.Register(
 		" const",
@@ -43,11 +43,11 @@
 
 type constHeader map[string]string
 
 type constZettel struct {
 	header  constHeader
-	content domain.Content
+	content zettel.Content
 }
 
 type constBox struct {
 	log      *logger.Logger
 	number   int
@@ -57,22 +57,22 @@
 
 func (*constBox) Location() string { return "const:" }
 
 func (*constBox) CanCreateZettel(context.Context) bool { return false }
 
-func (cb *constBox) CreateZettel(context.Context, domain.Zettel) (id.Zid, error) {
+func (cb *constBox) CreateZettel(context.Context, zettel.Zettel) (id.Zid, error) {
 	cb.log.Trace().Err(box.ErrReadOnly).Msg("CreateZettel")
 	return id.Invalid, box.ErrReadOnly
 }
 
-func (cb *constBox) GetZettel(_ context.Context, zid id.Zid) (domain.Zettel, error) {
+func (cb *constBox) GetZettel(_ context.Context, zid id.Zid) (zettel.Zettel, error) {
 	if z, ok := cb.zettel[zid]; ok {
 		cb.log.Trace().Msg("GetZettel")
-		return domain.Zettel{Meta: meta.NewWithData(zid, z.header), Content: z.content}, nil
+		return zettel.Zettel{Meta: meta.NewWithData(zid, z.header), Content: z.content}, nil
 	}
 	cb.log.Trace().Err(box.ErrNotFound).Msg("GetZettel")
-	return domain.Zettel{}, box.ErrNotFound
+	return zettel.Zettel{}, box.ErrNotFound
 }
 
 func (cb *constBox) GetMeta(_ context.Context, zid id.Zid) (*meta.Meta, error) {
 	if z, ok := cb.zettel[zid]; ok {
 		cb.log.Trace().Msg("GetMeta")
@@ -102,13 +102,13 @@
 		}
 	}
 	return nil
 }
 
-func (*constBox) CanUpdateZettel(context.Context, domain.Zettel) bool { return false }
+func (*constBox) CanUpdateZettel(context.Context, zettel.Zettel) bool { return false }
 
-func (cb *constBox) UpdateZettel(context.Context, domain.Zettel) error {
+func (cb *constBox) UpdateZettel(context.Context, zettel.Zettel) error {
 	cb.log.Trace().Err(box.ErrReadOnly).Msg("UpdateZettel")
 	return box.ErrReadOnly
 }
 
 func (cb *constBox) AllowRenameZettel(_ context.Context, zid id.Zid) bool {
@@ -149,11 +149,11 @@
 			api.KeyRole:       api.ValueRoleConfiguration,
 			api.KeySyntax:     meta.SyntaxNone,
 			api.KeyCreated:    "20200804111624",
 			api.KeyVisibility: api.ValueVisibilityOwner,
 		},
-		domain.NewContent(nil)},
+		zettel.NewContent(nil)},
 	id.MustParse(api.ZidLicense): {
 		constHeader{
 			api.KeyTitle:      "Zettelstore License",
 			api.KeyRole:       api.ValueRoleConfiguration,
 			api.KeySyntax:     meta.SyntaxText,
@@ -161,11 +161,11 @@
 			api.KeyLang:       api.ValueLangEN,
 			api.KeyModified:   "20220131153422",
 			api.KeyReadOnly:   api.ValueTrue,
 			api.KeyVisibility: api.ValueVisibilityPublic,
 		},
-		domain.NewContent(contentLicense)},
+		zettel.NewContent(contentLicense)},
 	id.MustParse(api.ZidAuthors): {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Contributors",
 			api.KeyRole:       api.ValueRoleConfiguration,
 			api.KeySyntax:     meta.SyntaxZmk,
@@ -172,11 +172,11 @@
 			api.KeyCreated:    "20210504135842",
 			api.KeyLang:       api.ValueLangEN,
 			api.KeyReadOnly:   api.ValueTrue,
 			api.KeyVisibility: api.ValueVisibilityLogin,
 		},
-		domain.NewContent(contentContributors)},
+		zettel.NewContent(contentContributors)},
 	id.MustParse(api.ZidDependencies): {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Dependencies",
 			api.KeyRole:       api.ValueRoleConfiguration,
 			api.KeySyntax:     meta.SyntaxZmk,
@@ -184,157 +184,165 @@
 			api.KeyReadOnly:   api.ValueTrue,
 			api.KeyVisibility: api.ValueVisibilityLogin,
 			api.KeyCreated:    "20210504135842",
 			api.KeyModified:   "20221013105100",
 		},
-		domain.NewContent(contentDependencies)},
+		zettel.NewContent(contentDependencies)},
+	id.BaseTemplateZid + 30000: {
+		constHeader{
+			api.KeyTitle:      "Zettelstore Base HTML Template (Mustache)",
+			api.KeyRole:       api.ValueRoleConfiguration,
+			api.KeySyntax:     meta.SyntaxMustache,
+			api.KeyCreated:    "20210504135842",
+			api.KeyModified:   "20230523142249",
+			api.KeyVisibility: api.ValueVisibilityExpert,
+		},
+		zettel.NewContent(contentBaseMustache)},
 	id.BaseTemplateZid: {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Base HTML Template",
 			api.KeyRole:       api.ValueRoleConfiguration,
-			api.KeySyntax:     meta.SyntaxMustache,
-			api.KeyCreated:    "20210504135842",
+			api.KeySyntax:     meta.SyntaxSxn,
+			api.KeyCreated:    "20230510155100",
+			api.KeyModified:   "20230523144403",
 			api.KeyVisibility: api.ValueVisibilityExpert,
 		},
-		domain.NewContent(contentBaseMustache)},
+		zettel.NewContent(contentBaseSxn)},
 	id.LoginTemplateZid: {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Login Form HTML Template",
 			api.KeyRole:       api.ValueRoleConfiguration,
-			api.KeySyntax:     meta.SyntaxMustache,
+			api.KeySyntax:     meta.SyntaxSxn,
 			api.KeyCreated:    "20200804111624",
+			api.KeyModified:   "20230527144100",
 			api.KeyVisibility: api.ValueVisibilityExpert,
 		},
-		domain.NewContent(contentLoginMustache)},
+		zettel.NewContent(contentLoginSxn)},
 	id.ZettelTemplateZid: {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Zettel HTML Template",
 			api.KeyRole:       api.ValueRoleConfiguration,
-			api.KeySyntax:     meta.SyntaxMustache,
-			api.KeyCreated:    "20200804111624",
+			api.KeySyntax:     meta.SyntaxSxn,
+			api.KeyCreated:    "20230510155300",
+			api.KeyModified:   "20230523212800",
 			api.KeyVisibility: api.ValueVisibilityExpert,
 		},
-		domain.NewContent(contentZettelMustache)},
+		zettel.NewContent(contentZettelSxn)},
 	id.InfoTemplateZid: {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Info HTML Template",
 			api.KeyRole:       api.ValueRoleConfiguration,
 			api.KeySyntax:     meta.SyntaxMustache,
 			api.KeyCreated:    "20200804111624",
 			api.KeyVisibility: api.ValueVisibilityExpert,
 		},
-		domain.NewContent(contentInfoMustache)},
-	id.ContextTemplateZid: {
-		constHeader{
-			api.KeyTitle:      "Zettelstore Context HTML Template",
-			api.KeyRole:       api.ValueRoleConfiguration,
-			api.KeySyntax:     meta.SyntaxMustache,
-			api.KeyCreated:    "20210218181140",
-			api.KeyVisibility: api.ValueVisibilityExpert,
-		},
-		domain.NewContent(contentContextMustache)},
+		zettel.NewContent(contentInfoMustache)},
 	id.FormTemplateZid: {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Form HTML Template",
 			api.KeyRole:       api.ValueRoleConfiguration,
-			api.KeySyntax:     meta.SyntaxMustache,
+			api.KeySyntax:     meta.SyntaxSxn,
 			api.KeyCreated:    "20200804111624",
+			api.KeyModified:   "20230528210200",
 			api.KeyVisibility: api.ValueVisibilityExpert,
 		},
-		domain.NewContent(contentFormMustache)},
+		zettel.NewContent(contentFormSxn)},
 	id.RenameTemplateZid: {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Rename Form HTML Template",
 			api.KeyRole:       api.ValueRoleConfiguration,
-			api.KeySyntax:     meta.SyntaxMustache,
+			api.KeySyntax:     meta.SyntaxSxn,
 			api.KeyCreated:    "20200804111624",
+			api.KeyModified:   "20230528174800",
 			api.KeyVisibility: api.ValueVisibilityExpert,
 		},
-		domain.NewContent(contentRenameMustache)},
+		zettel.NewContent(contentRenameSxn)},
 	id.DeleteTemplateZid: {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Delete HTML Template",
 			api.KeyRole:       api.ValueRoleConfiguration,
-			api.KeySyntax:     meta.SyntaxMustache,
+			api.KeySyntax:     meta.SyntaxSxn,
 			api.KeyCreated:    "20200804111624",
+			api.KeyModified:   "20230528154900",
 			api.KeyVisibility: api.ValueVisibilityExpert,
 		},
-		domain.NewContent(contentDeleteMustache)},
+		zettel.NewContent(contentDeleteSxn)},
 	id.ListTemplateZid: {
 		constHeader{
 			api.KeyTitle:      "Zettelstore List Zettel HTML Template",
 			api.KeyRole:       api.ValueRoleConfiguration,
-			api.KeySyntax:     meta.SyntaxMustache,
-			api.KeyCreated:    "20200804111624",
+			api.KeySyntax:     meta.SyntaxSxn,
+			api.KeyCreated:    "20230526221600",
 			api.KeyVisibility: api.ValueVisibilityExpert,
 		},
-		domain.NewContent(contentListZettelMustache)},
+		zettel.NewContent(contentListZettelSxn)},
 	id.ErrorTemplateZid: {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Error HTML Template",
 			api.KeyRole:       api.ValueRoleConfiguration,
-			api.KeySyntax:     meta.SyntaxMustache,
+			api.KeySyntax:     meta.SyntaxSxn,
 			api.KeyCreated:    "20210305133215",
+			api.KeyModified:   "20230527224800",
 			api.KeyVisibility: api.ValueVisibilityExpert,
 		},
-		domain.NewContent(contentErrorMustache)},
+		zettel.NewContent(contentErrorSxn)},
 	id.MustParse(api.ZidBaseCSS): {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Base CSS",
 			api.KeyRole:       api.ValueRoleConfiguration,
 			api.KeySyntax:     meta.SyntaxCSS,
 			api.KeyCreated:    "20200804111624",
 			api.KeyVisibility: api.ValueVisibilityPublic,
 		},
-		domain.NewContent(contentBaseCSS)},
+		zettel.NewContent(contentBaseCSS)},
 	id.MustParse(api.ZidUserCSS): {
 		constHeader{
 			api.KeyTitle:      "Zettelstore User CSS",
 			api.KeyRole:       api.ValueRoleConfiguration,
 			api.KeySyntax:     meta.SyntaxCSS,
 			api.KeyCreated:    "20210622110143",
 			api.KeyVisibility: api.ValueVisibilityPublic,
 		},
-		domain.NewContent([]byte("/* User-defined CSS */"))},
+		zettel.NewContent([]byte("/* User-defined CSS */"))},
 	id.RoleCSSMapZid: {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Role to CSS Map",
 			api.KeyRole:       api.ValueRoleConfiguration,
 			api.KeySyntax:     meta.SyntaxNone,
 			api.KeyCreated:    "20220321183214",
 			api.KeyVisibility: api.ValueVisibilityExpert,
 		},
-		domain.NewContent(nil)},
+		zettel.NewContent(nil)},
 	id.EmojiZid: {
 		constHeader{
 			api.KeyTitle:      "Zettelstore Generic Emoji",
 			api.KeyRole:       api.ValueRoleConfiguration,
 			api.KeySyntax:     meta.SyntaxGif,
 			api.KeyReadOnly:   api.ValueTrue,
 			api.KeyCreated:    "20210504175807",
 			api.KeyVisibility: api.ValueVisibilityPublic,
 		},
-		domain.NewContent(contentEmoji)},
+		zettel.NewContent(contentEmoji)},
 	id.TOCNewTemplateZid: {
 		constHeader{
 			api.KeyTitle:      "New Menu",
 			api.KeyRole:       api.ValueRoleConfiguration,
 			api.KeySyntax:     meta.SyntaxZmk,
 			api.KeyLang:       api.ValueLangEN,
 			api.KeyCreated:    "20210217161829",
 			api.KeyVisibility: api.ValueVisibilityCreator,
 		},
-		domain.NewContent(contentNewTOCZettel)},
+		zettel.NewContent(contentNewTOCZettel)},
 	id.MustParse(api.ZidTemplateNewZettel): {
 		constHeader{
 			api.KeyTitle:      "New Zettel",
 			api.KeyRole:       api.ValueRoleZettel,
 			api.KeySyntax:     meta.SyntaxZmk,
 			api.KeyCreated:    "20201028185209",
 			api.KeyVisibility: api.ValueVisibilityCreator,
 		},
-		domain.NewContent(nil)},
+		zettel.NewContent(nil)},
 	id.MustParse(api.ZidTemplateNewUser): {
 		constHeader{
 			api.KeyTitle:                       "New User",
 			api.KeyRole:                        api.ValueRoleConfiguration,
 			api.KeySyntax:                      meta.SyntaxNone,
@@ -342,20 +350,20 @@
 			meta.NewPrefix + api.KeyCredential: "",
 			meta.NewPrefix + api.KeyUserID:     "",
 			meta.NewPrefix + api.KeyUserRole:   api.ValueUserRoleReader,
 			api.KeyVisibility:                  api.ValueVisibilityOwner,
 		},
-		domain.NewContent(nil)},
+		zettel.NewContent(nil)},
 	id.DefaultHomeZid: {
 		constHeader{
 			api.KeyTitle:   "Home",
 			api.KeyRole:    api.ValueRoleZettel,
 			api.KeySyntax:  meta.SyntaxZmk,
 			api.KeyLang:    api.ValueLangEN,
 			api.KeyCreated: "20210210190757",
 		},
-		domain.NewContent(contentHomeZettel)},
+		zettel.NewContent(contentHomeZettel)},
 }
 
 //go:embed license.txt
 var contentLicense []byte
 
@@ -366,36 +374,36 @@
 var contentDependencies []byte
 
 //go:embed base.mustache
 var contentBaseMustache []byte
 
-//go:embed login.mustache
-var contentLoginMustache []byte
+//go:embed base.sxn
+var contentBaseSxn []byte
+
+//go:embed login.sxn
+var contentLoginSxn []byte
 
-//go:embed zettel.mustache
-var contentZettelMustache []byte
+//go:embed zettel.sxn
+var contentZettelSxn []byte
 
 //go:embed info.mustache
 var contentInfoMustache []byte
 
-//go:embed context.mustache
-var contentContextMustache []byte
-
-//go:embed form.mustache
-var contentFormMustache []byte
-
-//go:embed rename.mustache
-var contentRenameMustache []byte
-
-//go:embed delete.mustache
-var contentDeleteMustache []byte
-
-//go:embed listzettel.mustache
-var contentListZettelMustache []byte
-
-//go:embed error.mustache
-var contentErrorMustache []byte
+//go:embed form.sxn
+var contentFormSxn []byte
+
+//go:embed rename.sxn
+var contentRenameSxn []byte
+
+//go:embed delete.sxn
+var contentDeleteSxn []byte
+
+//go:embed listzettel.sxn
+var contentListZettelSxn []byte
+
+//go:embed error.sxn
+var contentErrorSxn []byte
 
 //go:embed base.css
 var contentBaseCSS []byte
 
 //go:embed emoji_spin.gif

DELETED box/constbox/context.mustache
Index: box/constbox/context.mustache
==================================================================
--- box/constbox/context.mustache
+++ box/constbox/context.mustache
@@ -1,13 +0,0 @@
-<article>
-<header>
-<h1>{{Title}}</h1>
-<div class="zs-meta">
-<a href="{{{InfoURL}}}">Info</a>
-&#183; <a href="?dir=backward">Backward</a>
-&#183; <a href="?dir=both">Both</a>
-&#183; <a href="?dir=forward">Forward</a>
-&#183; Cost:{{#Costs}}&#x2000;<a href="{{{URL}}}">{{{Text}}}</a>{{/Costs}}
-</div>
-</header>
-{{{Content}}}
-</article>

DELETED box/constbox/delete.mustache
Index: box/constbox/delete.mustache
==================================================================
--- box/constbox/delete.mustache
+++ box/constbox/delete.mustache
@@ -1,42 +0,0 @@
-<article>
-<header>
-<h1>Delete Zettel {{Zid}}</h1>
-</header>
-<p>Do you really want to delete this zettel?</p>
-{{#HasShadows}}
-<div class="zs-info">
-<h2>Infomation</h2>
-<p>If you delete this zettel, the previoulsy shadowed zettel from overlayed box {{ShadowedBox}} becomes available.</p>
-</div>
-{{/HasShadows}}
-{{#Incoming.Has}}
-<div class="zs-warning">
-<h2>Warning!</h2>
-<p>If you delete this zettel, incoming references from the following zettel will become invalid.</p>
-<ul>
-{{#Incoming.Links}}
-<li><a href="{{{URL}}}">{{Text}}</a></li>
-{{/Incoming.Links}}
-</ul>
-</div>
-{{/Incoming.Has}}
-{{#HasUselessFiles}}
-<div class="zs-warning">
-<h2>Warning!</h2>
-<p>Deleting this zettel will also delete the following files, so that they will not be interpreted as content for this zettel.</p>
-<ul>
-{{#UselessFiles}}
-<li>{{{.}}}</li>
-{{/UselessFiles}}
-</ul>
-</div>
-{{/HasUselessFiles}}
-<dl>
-{{#MetaPairs}}
-<dt>{{Key}}:</dt><dd>{{Value}}</dd>
-{{/MetaPairs}}
-</dl>
-<form method="POST">
-<input class="zs-primary" type="submit" value="Delete">
-</form>
-</article>

ADDED   box/constbox/delete.sxn
Index: box/constbox/delete.sxn
==================================================================
--- box/constbox/delete.sxn
+++ box/constbox/delete.sxn
@@ -0,0 +1,26 @@
+(article
+  (header (h1 "Delete Zettel " ,zid))
+  (p "Do you really want to delete this zettel?")
+  ,@(if shadowed-box
+    `((div (@ (class "zs-info"))
+      (h2 "Information")
+      (p "If you delete this zettel, the previously shadowed zettel from overlayed box " ,shadowed-box " becomes available.")
+    ))
+  )
+  ,@(if incoming
+    `((div (@ (class "zs-warning"))
+      (h2 "Warning!")
+      (p "If you delete this zettel, incoming references from the following zettel will become invalid.")
+      (ul ,@(map pair-to-href-li incoming))
+    ))
+  )
+  ,@(if useless
+    `((div (@ (class "zs-warning"))
+      (h2 "Warning!")
+      (p "Deleting this zettel will also delete the following files, so that they will not be interpreted as content for this zettel.")
+      (ul ,@(map (lambda (s) `(li ,s)) useless))
+    ))
+  )
+  ,(pairs-to-dl meta-pairs)
+  (form (@ (method "POST")) (input (@ (class "zs-primary") (type "submit") (value "Delete"))))
+)

DELETED box/constbox/error.mustache
Index: box/constbox/error.mustache
==================================================================
--- box/constbox/error.mustache
+++ box/constbox/error.mustache
@@ -1,6 +0,0 @@
-<article>
-<header>
-<h1>{{ErrorTitle}}</h1>
-</header>
-{{ErrorText}}
-</article>

ADDED   box/constbox/error.sxn
Index: box/constbox/error.sxn
==================================================================
--- box/constbox/error.sxn
+++ box/constbox/error.sxn
@@ -0,0 +1,4 @@
+(article
+  (header (h1 ,heading))
+  ,message
+)

DELETED box/constbox/form.mustache
Index: box/constbox/form.mustache
==================================================================
--- box/constbox/form.mustache
+++ box/constbox/form.mustache
@@ -1,55 +0,0 @@
-<article>
-<header>
-<h1>{{Heading}}</h1>
-</header>
-<form action="{{FormActionURL}}" method="POST" enctype="multipart/form-data">
-<div>
-<label for="zs-title">Title <a title="Main heading of this zettel. You can use inline zettelmarkup.">&#9432;</a></label>
-<input class="zs-input" type="text" id="zs-title" name="title" placeholder="Title.." value="{{MetaTitle}}" autofocus>
-</div>
-<div>
-<div>
-<label for="zs-role">Role <a title="One word, without spaces, to set the main role of this zettel.">&#9432;</a></label>
-<input class="zs-input" type="text" id="zs-role" {{#HasRoleData}}list="zs-role-data"{{/HasRoleData}} name="role" placeholder="role.." value="{{MetaRole}}">
-{{#HasRoleData}}
-<datalist id="zs-role-data">
-{{#RoleData}}
-<option value="{{.}}">
-{{/RoleData}}
-</datalist>
-{{/HasRoleData}}
-</div>
-<label for="zs-tags">Tags <a title="Tags must begin with an '#' sign. They are separated by spaces.">&#9432;</a></label>
-<input class="zs-input" type="text" id="zs-tags" name="tags" placeholder="#tag" value="{{MetaTags}}">
-</div>
-<div>
-<label for="zs-meta">Metadata <a title="Other metadata for this zettel. Each line contains a key/value pair, separated by a colon ':'.">&#9432;</a></label>
-<textarea class="zs-input" id="zs-meta" name="meta" rows="4" placeholder="metakey: metavalue">
-{{#MetaPairsRest}}
-{{Key}}: {{Value}}
-{{/MetaPairsRest}}
-</textarea>
-</div>
-<div>
-<label for="zs-syntax">Syntax <a title="Syntax of zettel content below, one word. Typically 'zmk' (for zettelmarkup).">&#9432;</a></label>
-<input class="zs-input" type="text" id="zs-syntax" {{#HasSyntaxData}}list="zs-syntax-data"{{/HasSyntaxData}} name="syntax" placeholder="syntax.." value="{{MetaSyntax}}">
-{{#HasSyntaxData}}
-<datalist id="zs-syntax-data">
-{{#SyntaxData}}
-<option value="{{.}}">
-{{/SyntaxData}}
-</datalist>
-{{/HasSyntaxData}}</div>
-<div>
-{{#IsTextContent}}
-<label for="zs-content">Content <a title="Content for this zettel, according to above syntax.">&#9432;</a></label>
-<textarea class="zs-input zs-content" id="zs-content" name="content" rows="20" placeholder="Your content..">{{Content}}</textarea>
-{{/IsTextContent}}
-</div>
-<div>
-<input class="zs-primary" type="submit" value="Submit">
-<input class="zs-secondary" type="submit" value="Save" formaction="?save">
-<input class="zs-upload" type="file" id="zs-file" name="file">
-</div>
-</form>
-</article>

ADDED   box/constbox/form.sxn
Index: box/constbox/form.sxn
==================================================================
--- box/constbox/form.sxn
+++ box/constbox/form.sxn
@@ -0,0 +1,46 @@
+(article
+  (header (h1 ,heading))
+  (form (@ (action ,form-action-url) (method "POST") (enctype "multipart/form-data"))
+  (div
+    (label (@ (for "zs-title")) "Title " (a (@ (title "Main heading of this zettel.")) (@H "&#9432;")))
+    (input (@ (class "zs-input") (type "text") (id "zs-title") (name "title") (placeholder "Title..") (value ,meta-title) (autofocus))))
+  (div
+    (label (@ (for "zs-role")) "Role " (a (@ (title "One word, without spaces, to set the main role of this zettel.")) (@H "&#9432;")))
+    (input (@ (class "zs-input") (type "text") (id "zs-role") (name "role") (placeholder "role..") (value ,meta-role)
+      ,@(if role-data '((list "zs-role-data")))
+    ))
+    ,@(if role-data
+      `((datalist (@ (id "zs-role-data"))
+        ,@(map (lambda (v) `(option (@ (value ,v)))) role-data)
+      ))
+    )
+  )
+  (div
+    (label (@ (for "zs-tags")) "Tags " (a (@ (title "Tags must begin with an '#' sign. They are separated by spaces.")) (@H "&#9432;")))
+    (input (@ (class "zs-input") (type "text") (id "zs-tags") (name "tags") (placeholder "#tag") (value ,meta-tags))))
+  (div
+    (label (@ (for "zs-meta")) "Metadata " (a (@ (title "Other metadata for this zettel. Each line contains a key/value pair, separated by a colon ':'.")) (@H "&#9432;")))
+    (textarea (@ (class "zs-input") (id "zs-meta") (name "meta") (rows "4") (placeholder "metakey: metavalue")) ,meta))
+  (div
+    (label (@ (for "zs-syntax")) "Syntax " (a (@ (title "Syntax of zettel content below, one word. Typically 'zmk' (for zettelmarkup).")) (@H "&#9432;")))
+    (input (@ (class "zs-input") (type "text") (id "zs-syntax") (name "syntax") (placeholder "syntax..") (value ,meta-syntax)
+      ,@(if syntax-data '((list "zs-syntax-data")))
+    ))
+    ,@(if syntax-data
+      `((datalist (@ (id "zs-syntax-data"))
+        ,@(map (lambda (v) `(option (@ (value ,v)))) syntax-data)
+      ))
+    )
+  )
+  ,@(if (bound? 'content)
+    `((div
+      (label (@ (for "zs-content")) "Content " (a (@ (title "Content for this zettel, according to above syntax.")) (@H "&#9432;")))
+      (textarea (@ (class "zs-input zs-content") (id "zs-content") (name "content") (rows "20") (placeholder "Zettel content..")) ,content)
+    ))
+  )
+  (div
+    (input (@ (class "zs-primary") (type "submit") (value "Submit")))
+    (input (@ (class "zs-secondary") (type "submit") (value "Save") (formaction "?save")))
+    (input (@ (class "zs-upload") (type "file") (id "zs-file") (name "file")))
+  ))
+)

Index: box/constbox/info.mustache
==================================================================
--- box/constbox/info.mustache
+++ box/constbox/info.mustache
@@ -68,7 +68,6 @@
 </table>
 {{#HasShadowLinks}}
 <h2>Shadowed Boxes</h2>
 <ul>{{#ShadowLinks}}<li>{{.}}</li>{{/ShadowLinks}}</ul>
 {{/HasShadowLinks}}
-{{#Endnotes}}{{{Endnotes}}}{{/Endnotes}}
 </article>

DELETED box/constbox/listzettel.mustache
Index: box/constbox/listzettel.mustache
==================================================================
--- box/constbox/listzettel.mustache
+++ box/constbox/listzettel.mustache
@@ -1,14 +0,0 @@
-<article>
-<header>
-<h1>{{Title}}</h1>
-</header>
-<form action="{{{SearchURL}}}">
-<input class="zs-input" type="text" placeholder="Search.." name="{{QueryKeyQuery}}" value="{{QueryValue}}">
-</form>
-{{{Content}}}
-{{#CanCreate}}<form action="{{{CreateURL}}}">
-<input type="hidden" name="{{QueryKeyQuery}}" value="{{QueryValue}}">
-<input type="hidden" name="{{QueryKeySeed}}" value="{{Seed}}">
-<input class="zs-primary" type="submit" value="Save As Zettel">
-</form>{{/CanCreate}}
-</article>

ADDED   box/constbox/listzettel.sxn
Index: box/constbox/listzettel.sxn
==================================================================
--- box/constbox/listzettel.sxn
+++ box/constbox/listzettel.sxn
@@ -0,0 +1,14 @@
+(article
+  (header (h1 ,heading))
+  (form (@ (action ,search-url))
+    (input (@ (class "zs-input") (type "text") (placeholder "Search..") (name ,query-key-query) (value ,query-value))))
+  ,@content
+  ,@endnotes
+  ,@(if can-create
+    `((form (@ (action ,create-url))
+      (input (@ (type "hidden") (name ,query-key-query) (value ,query-value)))
+      (input (@ (type "hidden") (name ,query-key-seed) (value ,seed)))
+      (input (@ (class "zs-primary") (type "submit") (value "Save As Zettel")))
+    ))
+  )
+)

DELETED box/constbox/login.mustache
Index: box/constbox/login.mustache
==================================================================
--- box/constbox/login.mustache
+++ box/constbox/login.mustache
@@ -1,19 +0,0 @@
-<article>
-<header>
-<h1>{{Title}}</h1>
-</header>
-{{#Retry}}
-<div class="zs-indication zs-error">Wrong user name / password. Try again.</div>
-{{/Retry}}
-<form method="POST" action="">
-<div>
-<label for="username">User name:</label>
-<input class="zs-input" type="text" id="username" name="username" placeholder="Your user name.." autofocus>
-</div>
-<div>
-<label for="password">Password:</label>
-<input class="zs-input" type="password" id="password" name="password" placeholder="Your password..">
-</div>
-<div><input class="zs-primary" type="submit" value="Login"></div>
-</form>
-</article>

ADDED   box/constbox/login.sxn
Index: box/constbox/login.sxn
==================================================================
--- box/constbox/login.sxn
+++ box/constbox/login.sxn
@@ -0,0 +1,14 @@
+(article
+  (header (h1 ,heading))
+  ,@(if retry '((div (@ (class "zs-indication zs-error")) "Wrong user name / password. Try again.")))
+  (form (@ (method "POST") (action ""))
+    (div
+      (label (@ (for "username")) "User name:")
+      (input (@ (class "zs-input") (type "text") (id "username") (name "username") (placeholder "Your user name..") (autofocus))))
+    (div
+      (label (@ (for "password")) "Password:")
+      (input (@ (class "zs-input") (type "password") (id "password") (name "password") (placeholder "Your password.."))))
+    (div
+      (input (@ (class "zs-primary") (type "submit") (value "Login"))))
+  )
+)

DELETED box/constbox/rename.mustache
Index: box/constbox/rename.mustache
==================================================================
--- box/constbox/rename.mustache
+++ box/constbox/rename.mustache
@@ -1,41 +0,0 @@
-<article>
-<header>
-<h1>Rename Zettel {{Zid}}</h1>
-</header>
-<p>Do you really want to rename this zettel?</p>
-{{#Incoming.Has}}
-<div class="zs-warning">
-<h2>Warning!</h2>
-<p>If you rename this zettel, incoming references from the following zettel will become invalid.</p>
-<ul>
-{{#Incoming.Links}}
-<li><a href="{{{URL}}}">{{Text}}</a></li>
-{{/Incoming.Links}}
-</ul>
-</div>
-{{/Incoming.Has}}
-{{#HasUselessFiles}}
-<div class="zs-warning">
-<h2>Warning!</h2>
-<p>Renaming this zettel will also delete the following files, so that they will not be interpreted as content for a zettel with identifier {{Zid}}.</p>
-<ul>
-{{#UselessFiles}}
-<li>{{{.}}}</li>
-{{/UselessFiles}}
-</ul>
-</div>
-{{/HasUselessFiles}}
-<form method="POST">
-<div>
-<label for="newid">New zettel id</label>
-<input class="zs-input" type="text" id="newzid" name="newzid" placeholder="ZID.." value="{{Zid}}" autofocus>
-</div>
-<input type="hidden" id="curzid" name="curzid" value="{{Zid}}">
-<div><input class="zs-primary" type="submit" value="Rename"></div>
-</form>
-<dl>
-{{#MetaPairs}}
-<dt>{{Key}}:</dt><dd>{{Value}}</dd>
-{{/MetaPairs}}
-</dl>
-</article>

ADDED   box/constbox/rename.sxn
Index: box/constbox/rename.sxn
==================================================================
--- box/constbox/rename.sxn
+++ box/constbox/rename.sxn
@@ -0,0 +1,26 @@
+(article
+  (header (h1 "Rename Zettel " ,zid))
+  (p "Do you really want to rename this zettel?")
+  ,@(if incoming
+    `((div (@ (class "zs-warning"))
+      (h2 "Warning!")
+      (p "If you rename this zettel, incoming references from the following zettel will become invalid.")
+      (ul ,@(map pair-to-href-li incoming))
+    ))
+  )
+  ,@(if useless
+    `((div (@ (class "zs-warning"))
+      (h2 "Warning!")
+      (p "Renaming this zettel will also delete the following files, so that they will not be interpreted as content for this zettel.")
+      (ul ,@(map (lambda (s) `(li ,s)) useless))
+    ))
+  )
+  (form (@ (method "POST"))
+    (input (@ (type "hidden" (id "curzid") (name "curzid") (value ,zid))))
+    (div
+      (label (@ (for "newid") "New zettel id"))
+      (input (@ (class "zs-input") (type "text") (id "newid") (name "newid") (placeholder "ZID..") (value ,zid) (autofocus))))
+    (div (input (@ (class "zs-primary") (type "submit") (value "Rename"))))
+  )
+  ,(pairs-to-dl meta-pairs)
+)

DELETED box/constbox/zettel.mustache
Index: box/constbox/zettel.mustache
==================================================================
--- box/constbox/zettel.mustache
+++ box/constbox/zettel.mustache
@@ -1,52 +0,0 @@
-<article>
-<header>
-<h1>{{Heading}}</h1>
-<div class="zs-meta">
-{{#CanWrite}}<a href="{{{EditURL}}}">Edit</a> &#183;{{/CanWrite}}
-{{Zid}} &#183;
-<a href="{{{InfoURL}}}">Info</a> &#183;
-(<a href="{{{RoleURL}}}">{{RoleText}}</a>)
-{{#Tags.Has}}&#183; {{#Tags.Links}} <a href="{{{URL}}}">{{Text}}</a>{{/Tags.Links}}{{/Tags.Has}}
-{{#CanCopy}}&#183; <a href="{{{CopyURL}}}">Copy</a>{{/CanCopy}}
-{{#CanVersion}}&#183; <a href="{{{VersionURL}}}">Version</a>{{/CanVersion}}
-{{#CanFolge}}&#183; <a href="{{{FolgeURL}}}">Folge</a>{{/CanFolge}}
-{{#PredecessorRefs}}<br>Predecessor: {{{PredecessorRefs}}}{{/PredecessorRefs}}
-{{#PrecursorRefs}}<br>Precursor: {{{PrecursorRefs}}}{{/PrecursorRefs}}
-{{#HasExtURL}}<br>URL: {{{ExtURL}}}{{/HasExtURL}}
-{{#Author}}<br>By {{Author}}{{/Author}}
-</div>
-</header>
-{{{Content}}}
-</article>
-{{#NeedBottomNav}}<nav>{{/NeedBottomNav}}
-{{#FolgeLinks.Has}}
-<details open>
-<summary>Folgezettel</summary>
-<ul>
-{{#FolgeLinks.Links}}
-<li><a href="{{{URL}}}">{{Text}}</a></li>
-{{/FolgeLinks.Links}}
-</ul>
-</details>
-{{/FolgeLinks.Has}}
-{{#BackLinks.Has}}
-<details open>
-<summary>Incoming</summary>
-<ul>
-{{#BackLinks.Links}}
-<li><a href="{{{URL}}}">{{Text}}</a></li>
-{{/BackLinks.Links}}
-</ul>
-</details>
-{{/BackLinks.Has}}
-{{#SuccessorLinks.Has}}
-<details open>
-<summary>Successors</summary>
-<ul>
-{{#SuccessorLinks.Links}}
-<li><a href="{{{URL}}}">{{Text}}</a></li>
-{{/SuccessorLinks.Links}}
-</ul>
-</details>
-{{/SuccessorLinks.Has}}
-{{#NeedBottomNav}}</nav>{{/NeedBottomNav}}

ADDED   box/constbox/zettel.sxn
Index: box/constbox/zettel.sxn
==================================================================
--- box/constbox/zettel.sxn
+++ box/constbox/zettel.sxn
@@ -0,0 +1,30 @@
+(article
+  (header
+    (h1 ,heading)
+    (div (@ (class "zs-meta"))
+      ,@(if can-write `((a (@ (href ,edit-url)) "Edit") (@H " &#183; ")))
+      ,zid (@H " &#183; ")
+      (a (@ (href ,info-url)) "Info") (@H " &#183; ")
+      "(" (a (@ (href ,role-url)) ,meta-role) ")"
+      ,@(if tag-refs `((@H " &#183; ") ,@tag-refs))
+      ,@(if can-copy `((@H " &#183; ") (a (@ (href ,copy-url)) "Copy")))
+      ,@(if can-version `((@H " &#183; ") (a (@ (href ,version-url)) "Version")))
+      ,@(if can-folge `((@H " &#183; ") (a (@ (href ,folge-url)) "Folge")))
+      ,@(if predecessor-refs `((br) "Predecessor: " ,predecessor-refs))
+      ,@(if precursor-refs `((br) "Precursor: " ,precursor-refs))
+      ,@(if superior-refs `((br) "Superior: " ,superior-refs))
+      ,@(if ext-url `((br) "URL: " ,ext-url))
+      ,@(let (author (and (bound? 'meta-author) meta-author)) (if author `((br) "By " ,author)))
+    )
+  )
+  ,@content
+  ,endnotes
+  ,@(if (or folge-links subordinate-links back-links successor-links)
+    `((nav
+      ,@(if folge-links `((details (@ (open)) (summary "Folgezettel") (ul ,@(map pair-to-href-li folge-links)))))
+      ,@(if subordinate-links `((details (@ (open)) (summary "Subordinates") (ul ,@(map pair-to-href-li subordinate-links)))))
+      ,@(if back-links `((details (@ (open)) (summary "Incoming") (ul ,@(map pair-to-href-li back-links)))))
+      ,@(if successor-links `((details (@ (open)) (summary "Successors") (ul ,@(map pair-to-href-li successor-links)))))
+     ))
+  )
+)

Index: box/dirbox/dirbox.go
==================================================================
--- box/dirbox/dirbox.go
+++ box/dirbox/dirbox.go
@@ -20,16 +20,16 @@
 	"sync"
 
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/box/manager"
 	"zettelstore.de/z/box/notify"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	manager.Register("dir", func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
 		var log *logger.Logger
@@ -221,11 +221,11 @@
 
 func (dp *dirBox) CanCreateZettel(_ context.Context) bool {
 	return !dp.readonly
 }
 
-func (dp *dirBox) CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
+func (dp *dirBox) CreateZettel(ctx context.Context, zettel zettel.Zettel) (id.Zid, error) {
 	if dp.readonly {
 		return id.Invalid, box.ErrReadOnly
 	}
 
 	newZid, err := dp.dirSrv.SetNewDirEntry()
@@ -244,20 +244,20 @@
 	dp.notifyChanged(meta.Zid)
 	dp.log.Trace().Err(err).Zid(meta.Zid).Msg("CreateZettel")
 	return meta.Zid, err
 }
 
-func (dp *dirBox) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
+func (dp *dirBox) GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error) {
 	entry := dp.dirSrv.GetDirEntry(zid)
 	if !entry.IsValid() {
-		return domain.Zettel{}, box.ErrNotFound
+		return zettel.Zettel{}, box.ErrNotFound
 	}
 	m, c, err := dp.srvGetMetaContent(ctx, entry, zid)
 	if err != nil {
-		return domain.Zettel{}, err
+		return zettel.Zettel{}, err
 	}
-	zettel := domain.Zettel{Meta: m, Content: domain.NewContent(c)}
+	zettel := zettel.Zettel{Meta: m, Content: zettel.NewContent(c)}
 	dp.log.Trace().Zid(zid).Msg("GetZettel")
 	return zettel, nil
 }
 
 func (dp *dirBox) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
@@ -301,15 +301,15 @@
 		handle(m)
 	}
 	return nil
 }
 
-func (dp *dirBox) CanUpdateZettel(context.Context, domain.Zettel) bool {
+func (dp *dirBox) CanUpdateZettel(context.Context, zettel.Zettel) bool {
 	return !dp.readonly
 }
 
-func (dp *dirBox) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
+func (dp *dirBox) UpdateZettel(ctx context.Context, zettel zettel.Zettel) error {
 	if dp.readonly {
 		return box.ErrReadOnly
 	}
 
 	meta := zettel.Meta
@@ -330,11 +330,11 @@
 	}
 	dp.log.Trace().Zid(zid).Err(err).Msg("UpdateZettel")
 	return err
 }
 
-func (dp *dirBox) updateEntryFromMetaContent(entry *notify.DirEntry, m *meta.Meta, content domain.Content) {
+func (dp *dirBox) updateEntryFromMetaContent(entry *notify.DirEntry, m *meta.Meta, content zettel.Content) {
 	entry.SetupFromMetaContent(m, content, dp.cdata.Config.GetZettelFileSyntax)
 }
 
 func (dp *dirBox) AllowRenameZettel(context.Context, id.Zid) bool {
 	return !dp.readonly
@@ -365,11 +365,11 @@
 	newEntry, err := dp.dirSrv.RenameDirEntry(curEntry, newZid)
 	if err != nil {
 		return err
 	}
 	oldMeta.Zid = newZid
-	newZettel := domain.Zettel{Meta: oldMeta, Content: domain.NewContent(oldContent)}
+	newZettel := zettel.Zettel{Meta: oldMeta, Content: zettel.NewContent(oldContent)}
 	if err = dp.srvSetZettel(ctx, &newEntry, newZettel); err != nil {
 		// "Rollback" rename. No error checking...
 		dp.dirSrv.RenameDirEntry(&newEntry, curZid)
 		return err
 	}

Index: box/dirbox/service.go
==================================================================
--- box/dirbox/service.go
+++ box/dirbox/service.go
@@ -17,16 +17,16 @@
 	"path/filepath"
 	"time"
 
 	"zettelstore.de/z/box/filebox"
 	"zettelstore.de/z/box/notify"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func fileService(i uint32, log *logger.Logger, dirPath string, cmds <-chan fileCmd) {
 	// Something may panic. Ensure a running service.
 	defer func() {
@@ -166,11 +166,11 @@
 
 // COMMAND: srvSetZettel ----------------------------------------
 //
 // Writes a new or exsting zettel.
 
-func (dp *dirBox) srvSetZettel(ctx context.Context, entry *notify.DirEntry, zettel domain.Zettel) error {
+func (dp *dirBox) srvSetZettel(ctx context.Context, entry *notify.DirEntry, zettel zettel.Zettel) error {
 	rc := make(chan resSetZettel, 1)
 	dp.getFileChan(zettel.Meta.Zid) <- &fileSetZettel{entry, zettel, rc}
 	ctx, cancel := context.WithTimeout(ctx, serviceTimeout)
 	defer cancel()
 	select {
@@ -181,11 +181,11 @@
 	}
 }
 
 type fileSetZettel struct {
 	entry  *notify.DirEntry
-	zettel domain.Zettel
+	zettel zettel.Zettel
 	rc     chan<- resSetZettel
 }
 type resSetZettel = error
 
 func (cmd *fileSetZettel) run(log *logger.Logger, dirPath string) {

Index: box/filebox/filebox.go
==================================================================
--- box/filebox/filebox.go
+++ box/filebox/filebox.go
@@ -18,13 +18,13 @@
 	"strings"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/box/manager"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	manager.Register("file", func(u *url.URL, cdata *manager.ConnectData) (box.ManagedBox, error) {
 		path := getFilepathFromURL(u)

Index: box/filebox/zipbox.go
==================================================================
--- box/filebox/zipbox.go
+++ box/filebox/zipbox.go
@@ -16,16 +16,16 @@
 	"io"
 	"strings"
 
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/box/notify"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type zipBox struct {
 	log      *logger.Logger
 	number   int
@@ -82,24 +82,24 @@
 	zb.dirSrv = nil
 }
 
 func (*zipBox) CanCreateZettel(context.Context) bool { return false }
 
-func (zb *zipBox) CreateZettel(context.Context, domain.Zettel) (id.Zid, error) {
+func (zb *zipBox) CreateZettel(context.Context, zettel.Zettel) (id.Zid, error) {
 	err := box.ErrReadOnly
 	zb.log.Trace().Err(err).Msg("CreateZettel")
 	return id.Invalid, err
 }
 
-func (zb *zipBox) GetZettel(_ context.Context, zid id.Zid) (domain.Zettel, error) {
+func (zb *zipBox) GetZettel(_ context.Context, zid id.Zid) (zettel.Zettel, error) {
 	entry := zb.dirSrv.GetDirEntry(zid)
 	if !entry.IsValid() {
-		return domain.Zettel{}, box.ErrNotFound
+		return zettel.Zettel{}, box.ErrNotFound
 	}
 	reader, err := zip.OpenReader(zb.name)
 	if err != nil {
-		return domain.Zettel{}, err
+		return zettel.Zettel{}, err
 	}
 	defer reader.Close()
 
 	var m *meta.Meta
 	var src []byte
@@ -110,11 +110,11 @@
 		if contentName == "" {
 			zb.log.Panic().Zid(zid).Msg("No meta, no content in zipBox.GetZettel")
 		}
 		src, err = readZipFileContent(reader, entry.ContentName)
 		if err != nil {
-			return domain.Zettel{}, err
+			return zettel.Zettel{}, err
 		}
 		if entry.HasMetaInContent() {
 			inp := input.NewInput(src)
 			m = meta.NewFromInput(zid, inp)
 			src = src[inp.Pos:]
@@ -122,24 +122,24 @@
 			m = CalcDefaultMeta(zid, entry.ContentExt)
 		}
 	} else {
 		m, err = readZipMetaFile(reader, zid, metaName)
 		if err != nil {
-			return domain.Zettel{}, err
+			return zettel.Zettel{}, err
 		}
 		inMeta = true
 		if contentName != "" {
 			src, err = readZipFileContent(reader, entry.ContentName)
 			if err != nil {
-				return domain.Zettel{}, err
+				return zettel.Zettel{}, err
 			}
 		}
 	}
 
 	CleanupMeta(m, zid, entry.ContentExt, inMeta, entry.UselessFiles)
 	zb.log.Trace().Zid(zid).Msg("GetZettel")
-	return domain.Zettel{Meta: m, Content: domain.NewContent(src)}, nil
+	return zettel.Zettel{Meta: m, Content: zettel.NewContent(src)}, nil
 }
 
 func (zb *zipBox) GetMeta(_ context.Context, zid id.Zid) (*meta.Meta, error) {
 	entry := zb.dirSrv.GetDirEntry(zid)
 	if !entry.IsValid() {
@@ -184,13 +184,13 @@
 		handle(m)
 	}
 	return nil
 }
 
-func (*zipBox) CanUpdateZettel(context.Context, domain.Zettel) bool { return false }
+func (*zipBox) CanUpdateZettel(context.Context, zettel.Zettel) bool { return false }
 
-func (zb *zipBox) UpdateZettel(context.Context, domain.Zettel) error {
+func (zb *zipBox) UpdateZettel(context.Context, zettel.Zettel) error {
 	err := box.ErrReadOnly
 	zb.log.Trace().Err(err).Msg("UpdateZettel")
 	return err
 }
 

Index: box/helper.go
==================================================================
--- box/helper.go
+++ box/helper.go
@@ -13,11 +13,11 @@
 import (
 	"net/url"
 	"strconv"
 	"time"
 
-	"zettelstore.de/z/domain/id"
+	"zettelstore.de/z/zettel/id"
 )
 
 // GetNewZid calculates a new and unused zettel identifier, based on the current date and time.
 func GetNewZid(testZid func(id.Zid) (bool, error)) (id.Zid, error) {
 	withSeconds := false

Index: box/manager/anteroom.go
==================================================================
--- box/manager/anteroom.go
+++ box/manager/anteroom.go
@@ -11,11 +11,11 @@
 package manager
 
 import (
 	"sync"
 
-	"zettelstore.de/z/domain/id"
+	"zettelstore.de/z/zettel/id"
 )
 
 type arAction int
 
 const (

Index: box/manager/anteroom_test.go
==================================================================
--- box/manager/anteroom_test.go
+++ box/manager/anteroom_test.go
@@ -11,11 +11,11 @@
 package manager
 
 import (
 	"testing"
 
-	"zettelstore.de/z/domain/id"
+	"zettelstore.de/z/zettel/id"
 )
 
 func TestSimple(t *testing.T) {
 	t.Parallel()
 	ar := newAnterooms(2)

Index: box/manager/box.go
==================================================================
--- box/manager/box.go
+++ box/manager/box.go
@@ -14,14 +14,14 @@
 	"context"
 	"errors"
 	"strings"
 
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Conatains all box.Box related functions
 
 // Location returns some information where the box is located.
@@ -45,11 +45,11 @@
 	defer mgr.mgrMx.RUnlock()
 	return mgr.State() == box.StartStateStarted && mgr.boxes[0].CanCreateZettel(ctx)
 }
 
 // CreateZettel creates a new zettel.
-func (mgr *Manager) CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
+func (mgr *Manager) CreateZettel(ctx context.Context, zettel zettel.Zettel) (id.Zid, error) {
 	mgr.mgrLog.Debug().Msg("CreateZettel")
 	if mgr.State() != box.StartStateStarted {
 		return id.Invalid, box.ErrStopped
 	}
 	mgr.mgrMx.RLock()
@@ -56,14 +56,14 @@
 	defer mgr.mgrMx.RUnlock()
 	return mgr.boxes[0].CreateZettel(ctx, zettel)
 }
 
 // GetZettel retrieves a specific zettel.
-func (mgr *Manager) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
+func (mgr *Manager) GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error) {
 	mgr.mgrLog.Debug().Zid(zid).Msg("GetZettel")
 	if mgr.State() != box.StartStateStarted {
-		return domain.Zettel{}, box.ErrStopped
+		return zettel.Zettel{}, box.ErrStopped
 	}
 	mgr.mgrMx.RLock()
 	defer mgr.mgrMx.RUnlock()
 	for i, p := range mgr.boxes {
 		if z, err := p.GetZettel(ctx, zid); err != box.ErrNotFound {
@@ -71,22 +71,22 @@
 				mgr.Enrich(ctx, z.Meta, i+1)
 			}
 			return z, err
 		}
 	}
-	return domain.Zettel{}, box.ErrNotFound
+	return zettel.Zettel{}, box.ErrNotFound
 }
 
 // GetAllZettel retrieves a specific zettel from all managed boxes.
-func (mgr *Manager) GetAllZettel(ctx context.Context, zid id.Zid) ([]domain.Zettel, error) {
+func (mgr *Manager) GetAllZettel(ctx context.Context, zid id.Zid) ([]zettel.Zettel, error) {
 	mgr.mgrLog.Debug().Zid(zid).Msg("GetAllZettel")
 	if mgr.State() != box.StartStateStarted {
 		return nil, box.ErrStopped
 	}
 	mgr.mgrMx.RLock()
 	defer mgr.mgrMx.RUnlock()
-	var result []domain.Zettel
+	var result []zettel.Zettel
 	for i, p := range mgr.boxes {
 		if z, err := p.GetZettel(ctx, zid); err == nil {
 			mgr.Enrich(ctx, z.Meta, i+1)
 			result = append(result, z)
 		}
@@ -164,12 +164,21 @@
 	if mgr.State() != box.StartStateStarted {
 		return nil, box.ErrStopped
 	}
 	mgr.mgrMx.RLock()
 	defer mgr.mgrMx.RUnlock()
-
-	compSearch := q.RetrieveAndCompile(mgr)
+	return mgr.doSelectMeta(ctx, q)
+}
+func (mgr *Manager) doSelectMeta(ctx context.Context, q *query.Query) ([]*meta.Meta, error) {
+	compSearch, err := q.RetrieveAndCompile(ctx, mgr, mgr.doGetMeta, mgr.doSelectMeta)
+	if err != nil {
+		return nil, err
+	}
+	if result := compSearch.Result(); result != nil {
+		mgr.mgrLog.Trace().Int("count", int64(len(result))).Msg("found without ApplyMeta")
+		return result, nil
+	}
 	selected := metaMap{}
 	for _, term := range compSearch.Terms {
 		rejected := id.Set{}
 		handleMeta := func(m *meta.Meta) {
 			zid := m.Zid
@@ -188,31 +197,33 @@
 				rejected.Zid(zid)
 				mgr.mgrLog.Trace().Zid(zid).Msg("SelectMeta/reject")
 			}
 		}
 		for _, p := range mgr.boxes {
-			if err := p.ApplyMeta(ctx, handleMeta, term.Retrieve); err != nil {
-				return nil, err
+			if err2 := p.ApplyMeta(ctx, handleMeta, term.Retrieve); err2 != nil {
+				return nil, err2
 			}
 		}
 	}
 	result := make([]*meta.Meta, 0, len(selected))
 	for _, m := range selected {
 		result = append(result, m)
 	}
-	return q.AfterSearch(result), nil
+	result = compSearch.AfterSearch(result)
+	mgr.mgrLog.Trace().Int("count", int64(len(result))).Msg("found with ApplyMeta")
+	return result, nil
 }
 
 // CanUpdateZettel returns true, if box could possibly update the given zettel.
-func (mgr *Manager) CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool {
+func (mgr *Manager) CanUpdateZettel(ctx context.Context, zettel zettel.Zettel) bool {
 	mgr.mgrMx.RLock()
 	defer mgr.mgrMx.RUnlock()
 	return mgr.State() == box.StartStateStarted && mgr.boxes[0].CanUpdateZettel(ctx, zettel)
 }
 
 // UpdateZettel updates an existing zettel.
-func (mgr *Manager) UpdateZettel(ctx context.Context, zettel domain.Zettel) error {
+func (mgr *Manager) UpdateZettel(ctx context.Context, zettel zettel.Zettel) error {
 	mgr.mgrLog.Debug().Zid(zettel.Meta.Zid).Msg("UpdateZettel")
 	if mgr.State() != box.StartStateStarted {
 		return box.ErrStopped
 	}
 	// Remove all (computed) properties from metadata before storing the zettel.

Index: box/manager/collect.go
==================================================================
--- box/manager/collect.go
+++ box/manager/collect.go
@@ -13,12 +13,12 @@
 import (
 	"strings"
 
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/box/manager/store"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/id"
 )
 
 type collectData struct {
 	refs  id.Set
 	words store.WordSet

Index: box/manager/enrich.go
==================================================================
--- box/manager/enrich.go
+++ box/manager/enrich.go
@@ -14,12 +14,12 @@
 	"context"
 	"strconv"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Enrich computes additional properties and updates the given metadata.
 func (mgr *Manager) Enrich(ctx context.Context, m *meta.Meta, boxNumber int) {
 

Index: box/manager/indexer.go
==================================================================
--- box/manager/indexer.go
+++ box/manager/indexer.go
@@ -16,16 +16,16 @@
 	"net/url"
 	"time"
 
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/box/manager/store"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // SearchEqual returns all zettel that contains the given exact word.
 // The word must be normalized through Unicode NKFD, trimmed and not empty.
 func (mgr *Manager) SearchEqual(word string) id.Set {
@@ -155,11 +155,11 @@
 		return false
 	}
 	return true
 }
 
-func (mgr *Manager) idxUpdateZettel(ctx context.Context, zettel domain.Zettel) {
+func (mgr *Manager) idxUpdateZettel(ctx context.Context, zettel zettel.Zettel) {
 	var cData collectData
 	cData.initialize()
 	collectZettelIndexData(parser.ParseZettel(ctx, zettel, "", mgr.rtConfig), &cData)
 
 	m := zettel.Meta

Index: box/manager/manager.go
==================================================================
--- box/manager/manager.go
+++ box/manager/manager.go
@@ -22,15 +22,15 @@
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/box/manager/memstore"
 	"zettelstore.de/z/box/manager/store"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // ConnectData contains all administration related values.
 type ConnectData struct {
 	Number   int // number of the box, starting with 1.
@@ -299,20 +299,32 @@
 	}
 	mgr.idxAr.Reset() // Ensure an initial index run
 	mgr.done = make(chan struct{})
 	go mgr.notifier()
 
-	for !mgr.allBoxesStarted() {
-		mgr.mgrLog.Trace().Msg("Wait for boxes to start")
-		time.Sleep(time.Second)
-	}
+	mgr.waitBoxesAreStarted()
 	mgr.setState(box.StartStateStarted)
 	mgr.notifyObserver(&box.UpdateInfo{Box: mgr, Reason: box.OnReady})
 
 	go mgr.idxIndexer()
 	return nil
 }
+
+func (mgr *Manager) waitBoxesAreStarted() {
+	const waitTime = 10 * time.Millisecond
+	const waitLoop = int(1 * time.Second / waitTime)
+	for i := 1; !mgr.allBoxesStarted(); i++ {
+		if i%waitLoop == 0 {
+			if time.Duration(i)*waitTime > time.Minute {
+				mgr.mgrLog.Warn().Msg("Waiting for more than one minute to start")
+			} else {
+				mgr.mgrLog.Trace().Msg("Wait for boxes to start")
+			}
+		}
+		time.Sleep(waitTime)
+	}
+}
 
 func (mgr *Manager) allBoxesStarted() bool {
 	for _, bx := range mgr.boxes {
 		if b, ok := bx.(box.StartStopper); ok && b.State() != box.StartStateStarted {
 			return false

Index: box/manager/memstore/memstore.go
==================================================================
--- box/manager/memstore/memstore.go
+++ box/manager/memstore/memstore.go
@@ -20,12 +20,12 @@
 	"sync"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/c/maps"
 	"zettelstore.de/z/box/manager/store"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type metaRefs struct {
 	forward  id.Slice
 	backward id.Slice

Index: box/manager/memstore/refs.go
==================================================================
--- box/manager/memstore/refs.go
+++ box/manager/memstore/refs.go
@@ -8,11 +8,11 @@
 // under this license.
 //-----------------------------------------------------------------------------
 
 package memstore
 
-import "zettelstore.de/z/domain/id"
+import "zettelstore.de/z/zettel/id"
 
 func refsDiff(refsN, refsO id.Slice) (newRefs, remRefs id.Slice) {
 	npos, opos := 0, 0
 	for npos < len(refsN) && opos < len(refsO) {
 		rn, ro := refsN[npos], refsO[opos]

Index: box/manager/memstore/refs_test.go
==================================================================
--- box/manager/memstore/refs_test.go
+++ box/manager/memstore/refs_test.go
@@ -11,11 +11,11 @@
 package memstore
 
 import (
 	"testing"
 
-	"zettelstore.de/z/domain/id"
+	"zettelstore.de/z/zettel/id"
 )
 
 func assertRefs(t *testing.T, i int, got, exp id.Slice) {
 	t.Helper()
 	if got == nil && exp != nil {

Index: box/manager/store/store.go
==================================================================
--- box/manager/store/store.go
+++ box/manager/store/store.go
@@ -13,13 +13,13 @@
 
 import (
 	"context"
 	"io"
 
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Stats records statistics about the store.
 type Stats struct {
 	// Zettel is the number of zettel managed by the indexer.

Index: box/manager/store/zettel.go
==================================================================
--- box/manager/store/zettel.go
+++ box/manager/store/zettel.go
@@ -8,11 +8,11 @@
 // under this license.
 //-----------------------------------------------------------------------------
 
 package store
 
-import "zettelstore.de/z/domain/id"
+import "zettelstore.de/z/zettel/id"
 
 // ZettelIndex contains all index data of a zettel.
 type ZettelIndex struct {
 	Zid      id.Zid            // zid of the indexed zettel
 	backrefs id.Set            // set of back references

Index: box/membox/membox.go
==================================================================
--- box/membox/membox.go
+++ box/membox/membox.go
@@ -16,16 +16,16 @@
 	"net/url"
 	"sync"
 
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/box/manager"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	manager.Register(
 		"mem",
@@ -46,11 +46,11 @@
 	u         *url.URL
 	cdata     manager.ConnectData
 	maxZettel int
 	maxBytes  int
 	mx        sync.RWMutex // Protects the following fields
-	zettel    map[id.Zid]domain.Zettel
+	zettel    map[id.Zid]zettel.Zettel
 	curBytes  int
 }
 
 func (mb *memBox) notifyChanged(zid id.Zid) {
 	if chci := mb.cdata.Notify; chci != nil {
@@ -71,11 +71,11 @@
 	return box.StartStateStarted
 }
 
 func (mb *memBox) Start(context.Context) error {
 	mb.mx.Lock()
-	mb.zettel = make(map[id.Zid]domain.Zettel)
+	mb.zettel = make(map[id.Zid]zettel.Zettel)
 	mb.curBytes = 0
 	mb.mx.Unlock()
 	mb.log.Trace().Int("max-zettel", int64(mb.maxZettel)).Int("max-bytes", int64(mb.maxBytes)).Msg("Start Box")
 	return nil
 }
@@ -90,11 +90,11 @@
 	mb.mx.RLock()
 	defer mb.mx.RUnlock()
 	return len(mb.zettel) < mb.maxZettel
 }
 
-func (mb *memBox) CreateZettel(_ context.Context, zettel domain.Zettel) (id.Zid, error) {
+func (mb *memBox) CreateZettel(_ context.Context, zettel zettel.Zettel) (id.Zid, error) {
 	mb.mx.Lock()
 	newBytes := mb.curBytes + zettel.Length()
 	if mb.maxZettel < len(mb.zettel) || mb.maxBytes < newBytes {
 		mb.mx.Unlock()
 		return id.Invalid, box.ErrCapacity
@@ -116,20 +116,20 @@
 	mb.notifyChanged(zid)
 	mb.log.Trace().Zid(zid).Msg("CreateZettel")
 	return zid, nil
 }
 
-func (mb *memBox) GetZettel(_ context.Context, zid id.Zid) (domain.Zettel, error) {
+func (mb *memBox) GetZettel(_ context.Context, zid id.Zid) (zettel.Zettel, error) {
 	mb.mx.RLock()
-	zettel, ok := mb.zettel[zid]
+	z, ok := mb.zettel[zid]
 	mb.mx.RUnlock()
 	if !ok {
-		return domain.Zettel{}, box.ErrNotFound
+		return zettel.Zettel{}, box.ErrNotFound
 	}
-	zettel.Meta = zettel.Meta.Clone()
+	z.Meta = z.Meta.Clone()
 	mb.log.Trace().Msg("GetZettel")
-	return zettel, nil
+	return z, nil
 }
 
 func (mb *memBox) GetMeta(_ context.Context, zid id.Zid) (*meta.Meta, error) {
 	mb.mx.RLock()
 	zettel, ok := mb.zettel[zid]
@@ -165,11 +165,11 @@
 		}
 	}
 	return nil
 }
 
-func (mb *memBox) CanUpdateZettel(_ context.Context, zettel domain.Zettel) bool {
+func (mb *memBox) CanUpdateZettel(_ context.Context, zettel zettel.Zettel) bool {
 	mb.mx.RLock()
 	defer mb.mx.RUnlock()
 	zid := zettel.Meta.Zid
 	if !zid.IsValid() {
 		return false
@@ -180,11 +180,11 @@
 		newBytes -= prevZettel.Length()
 	}
 	return newBytes < mb.maxBytes
 }
 
-func (mb *memBox) UpdateZettel(_ context.Context, zettel domain.Zettel) error {
+func (mb *memBox) UpdateZettel(_ context.Context, zettel zettel.Zettel) error {
 	m := zettel.Meta.Clone()
 	if !m.Zid.IsValid() {
 		return &box.ErrInvalidID{Zid: m.Zid}
 	}
 

Index: box/notify/directory.go
==================================================================
--- box/notify/directory.go
+++ box/notify/directory.go
@@ -17,16 +17,16 @@
 	"regexp"
 	"strings"
 	"sync"
 
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/query"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/id"
 )
 
 type entrySet map[id.Zid]*DirEntry
 
 // DirServiceState signal the internal state of the service.

Index: box/notify/directory_test.go
==================================================================
--- box/notify/directory_test.go
+++ box/notify/directory_test.go
@@ -11,18 +11,18 @@
 package notify
 
 import (
 	"testing"
 
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	_ "zettelstore.de/z/parser/blob"       // Allow to use BLOB parser.
 	_ "zettelstore.de/z/parser/draw"       // Allow to use draw parser.
 	_ "zettelstore.de/z/parser/markdown"   // Allow to use markdown parser.
 	_ "zettelstore.de/z/parser/none"       // Allow to use none parser.
 	_ "zettelstore.de/z/parser/plain"      // Allow to use plain parser.
 	_ "zettelstore.de/z/parser/zettelmark" // Allow to use zettelmark parser.
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func TestSeekZid(t *testing.T) {
 	testcases := []struct {
 		name string

Index: box/notify/entry.go
==================================================================
--- box/notify/entry.go
+++ box/notify/entry.go
@@ -12,14 +12,14 @@
 
 import (
 	"path/filepath"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 const (
 	extZettel = "zettel" // file contains metadata and content
 	extBin    = "bin"    // file contains binary content
@@ -46,11 +46,11 @@
 func (e *DirEntry) HasMetaInContent() bool {
 	return e.IsValid() && extIsMetaAndContent(e.ContentExt)
 }
 
 // SetupFromMetaContent fills entry data based on metadata and zettel content.
-func (e *DirEntry) SetupFromMetaContent(m *meta.Meta, content domain.Content, getZettelFileSyntax func() []string) {
+func (e *DirEntry) SetupFromMetaContent(m *meta.Meta, content zettel.Content, getZettelFileSyntax func() []string) {
 	if e.Zid != m.Zid {
 		panic("Zid differ")
 	}
 	if contentName := e.ContentName; contentName != "" {
 		if !extIsMetaAndContent(e.ContentExt) && e.MetaName == "" {
@@ -78,11 +78,11 @@
 			e.MetaName = e.calcBaseName(e.ContentName)
 		}
 	}
 }
 
-func contentExtWithMeta(syntax string, content domain.Content) string {
+func contentExtWithMeta(syntax string, content zettel.Content) string {
 	p := parser.Get(syntax)
 	if content.IsBinary() {
 		if p.IsImageFormat {
 			return syntax
 		}

Index: cmd/cmd_file.go
==================================================================
--- cmd/cmd_file.go
+++ cmd/cmd_file.go
@@ -16,16 +16,16 @@
 	"fmt"
 	"io"
 	"os"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // ---------- Subcommand: file -----------------------------------------------
 
 func cmdFile(fs *flag.FlagSet) (int, error) {
@@ -34,13 +34,13 @@
 	if m == nil {
 		return 2, err
 	}
 	z := parser.ParseZettel(
 		context.Background(),
-		domain.Zettel{
+		zettel.Zettel{
 			Meta:    m,
-			Content: domain.NewContent(inp.Src[inp.Pos:]),
+			Content: zettel.NewContent(inp.Src[inp.Pos:]),
 		},
 		m.GetDefault(api.KeySyntax, meta.SyntaxZmk),
 		nil,
 	)
 	encdr := encoder.Create(api.Encoder(enc))

Index: cmd/cmd_password.go
==================================================================
--- cmd/cmd_password.go
+++ cmd/cmd_password.go
@@ -17,11 +17,11 @@
 
 	"golang.org/x/term"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/auth/cred"
-	"zettelstore.de/z/domain/id"
+	"zettelstore.de/z/zettel/id"
 )
 
 // ---------- Subcommand: password -------------------------------------------
 
 func cmdPassword(fs *flag.FlagSet) (int, error) {

Index: cmd/cmd_run.go
==================================================================
--- cmd/cmd_run.go
+++ cmd/cmd_run.go
@@ -16,16 +16,16 @@
 	"net/http"
 
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter/api"
 	"zettelstore.de/z/web/adapter/webui"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // ---------- Subcommand: run ------------------------------------------------
 
 func flgRun(fs *flag.FlagSet) {
@@ -65,11 +65,10 @@
 	ucParseZettel := usecase.NewParseZettel(rtConfig, ucGetZettel)
 	ucListMeta := usecase.NewListMeta(protectedBoxManager)
 	ucEvaluate := usecase.NewEvaluate(rtConfig, ucGetZettel, ucGetMeta, ucListMeta)
 	ucListSyntax := usecase.NewListSyntax(protectedBoxManager)
 	ucListRoles := usecase.NewListRoles(protectedBoxManager)
-	ucZettelContext := usecase.NewZettelContext(protectedBoxManager, rtConfig)
 	ucDelete := usecase.NewDeleteZettel(logUc, protectedBoxManager)
 	ucUpdate := usecase.NewUpdateZettel(logUc, protectedBoxManager)
 	ucRename := usecase.NewRenameZettel(logUc, protectedBoxManager)
 	ucUnlinkedRefs := usecase.NewUnlinkedReferences(protectedBoxManager, rtConfig)
 	ucRefresh := usecase.NewRefresh(logUc, protectedBoxManager)
@@ -102,28 +101,25 @@
 		webSrv.AddZettelRoute('d', server.MethodPost, wui.MakePostDeleteZettelHandler(&ucDelete))
 		webSrv.AddZettelRoute('e', server.MethodGet, wui.MakeEditGetZettelHandler(ucGetZettel, ucListRoles, ucListSyntax))
 		webSrv.AddZettelRoute('e', server.MethodPost, wui.MakeEditSetZettelHandler(&ucUpdate))
 	}
 	webSrv.AddListRoute('g', server.MethodGet, wui.MakeGetGoActionHandler(&ucRefresh))
-	webSrv.AddListRoute('h', server.MethodGet, wui.MakeListHTMLMetaHandler(ucListMeta, &ucEvaluate))
+	webSrv.AddListRoute('h', server.MethodGet, wui.MakeListHTMLMetaHandler(ucListMeta))
 	webSrv.AddZettelRoute('h', server.MethodGet, wui.MakeGetHTMLZettelHandler(&ucEvaluate, ucGetMeta))
 	webSrv.AddListRoute('i', server.MethodGet, wui.MakeGetLoginOutHandler())
 	webSrv.AddListRoute('i', server.MethodPost, wui.MakePostLoginHandler(&ucAuthenticate))
 	webSrv.AddZettelRoute('i', server.MethodGet, wui.MakeGetInfoHandler(
 		ucParseZettel, &ucEvaluate, ucGetMeta, ucGetAllMeta, ucUnlinkedRefs))
-	webSrv.AddZettelRoute('k', server.MethodGet, wui.MakeZettelContextHandler(
-		ucZettelContext, &ucEvaluate))
 
 	// API
 	webSrv.AddListRoute('a', server.MethodPost, a.MakePostLoginHandler(&ucAuthenticate))
 	webSrv.AddListRoute('a', server.MethodPut, a.MakeRenewAuthHandler())
 	webSrv.AddZettelRoute('o', server.MethodGet, a.MakeGetOrderHandler(
 		usecase.NewZettelOrder(protectedBoxManager, ucEvaluate)))
 	webSrv.AddZettelRoute('u', server.MethodGet, a.MakeListUnlinkedMetaHandler(ucGetMeta, ucUnlinkedRefs))
 	webSrv.AddListRoute('x', server.MethodGet, a.MakeGetDataHandler(ucVersion))
 	webSrv.AddListRoute('x', server.MethodPost, a.MakePostCommandHandler(&ucIsAuth, &ucRefresh))
-	webSrv.AddZettelRoute('x', server.MethodGet, a.MakeZettelContextHandler(ucZettelContext))
 	webSrv.AddListRoute('z', server.MethodGet, a.MakeQueryHandler(ucListMeta))
 	webSrv.AddZettelRoute('z', server.MethodGet, a.MakeGetZettelHandler(ucGetMeta, ucGetZettel, ucParseZettel, ucEvaluate))
 	if !authManager.IsReadonly() {
 		webSrv.AddListRoute('z', server.MethodPost, a.MakePostCreateZettelHandler(&ucCreateZettel))
 		webSrv.AddZettelRoute('z', server.MethodPut, a.MakeUpdateZettelHandler(&ucUpdate))

Index: cmd/main.go
==================================================================
--- cmd/main.go
+++ cmd/main.go
@@ -27,16 +27,16 @@
 	"zettelstore.de/z/auth/impl"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/box/compbox"
 	"zettelstore.de/z/box/manager"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 const strRunSimple = "run-simple"
 
 func init() {

Index: cmd/register.go
==================================================================
--- cmd/register.go
+++ cmd/register.go
@@ -18,12 +18,12 @@
 	_ "zettelstore.de/z/box/dirbox"        // Allow to use directory box.
 	_ "zettelstore.de/z/box/filebox"       // Allow to use file box.
 	_ "zettelstore.de/z/box/membox"        // Allow to use in-memory box.
 	_ "zettelstore.de/z/encoder/htmlenc"   // Allow to use HTML encoder.
 	_ "zettelstore.de/z/encoder/mdenc"     // Allow to use markdown encoder.
-	_ "zettelstore.de/z/encoder/sexprenc"  // Allow to use sexpr encoder.
 	_ "zettelstore.de/z/encoder/shtmlenc"  // Allow to use SHTML encoder.
+	_ "zettelstore.de/z/encoder/szenc"     // Allow to use Sz encoder.
 	_ "zettelstore.de/z/encoder/textenc"   // Allow to use text encoder.
 	_ "zettelstore.de/z/encoder/zmkenc"    // Allow to use zmk encoder.
 	_ "zettelstore.de/z/kernel/impl"       // Allow kernel implementation to create itself
 	_ "zettelstore.de/z/parser/blob"       // Allow to use BLOB parser.
 	_ "zettelstore.de/z/parser/draw"       // Allow to use draw parser.

Index: config/config.go
==================================================================
--- config/config.go
+++ config/config.go
@@ -12,11 +12,11 @@
 package config
 
 import (
 	"context"
 
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Key values that are supported by Config.Get
 const (
 	KeyFooterZettel = "footer-zettel"

Index: docs/development/20210916193200.zettel
==================================================================
--- docs/development/20210916193200.zettel
+++ docs/development/20210916193200.zettel
@@ -1,23 +1,28 @@
 id: 20210916193200
 title: Required Software
 role: zettel
 syntax: zmk
 created: 20210916193200
-modified: 20230327165135
+modified: 20230405150541
 
 The following software must be installed:
 
 * A current, supported [[release of Go|https://go.dev/doc/devel/release]],
-* [[shadow|https://pkg.go.dev/golang.org/x/tools/go/analysis/passes/shadow]] via ``go install golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow@latest``,
-* [[staticcheck|https://staticcheck.io/]] via ``go install honnef.co/go/tools/cmd/staticcheck@latest``,
-* [[unparam|https://mvdan.cc/unparam]][^[[GitHub|https://github.com/mvdan/unparam]]] via ``go install mvdan.cc/unparam@latest``,
-* [[govulncheck|https://golang.org/x/vuln/cmd/govulncheck]] via ``go install golang.org/x/vuln/cmd/govulncheck@latest``,
 * [[Fossil|https://fossil-scm.org/]],
 * [[Git|https://git-scm.org/]] (most dependencies are accessible via Git only).
 
 Make sure that the software is in your path, e.g. via:
-
 ```sh
 export PATH=$PATH:/usr/local/go/bin
 export PATH=$PATH:$(go env GOPATH)/bin
 ```
+
+The internal build tool need the following software.
+It can be installed / updated via the build tool itself: ``go run tools/build.go tools``.
+
+Otherwise you can install the software by hand:
+
+* [[shadow|https://pkg.go.dev/golang.org/x/tools/go/analysis/passes/shadow]] via ``go install golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow@latest``,
+* [[staticcheck|https://staticcheck.io/]] via ``go install honnef.co/go/tools/cmd/staticcheck@latest``,
+* [[unparam|https://mvdan.cc/unparam]][^[[GitHub|https://github.com/mvdan/unparam]]] via ``go install mvdan.cc/unparam@latest``,
+* [[govulncheck|https://golang.org/x/vuln/cmd/govulncheck]] via ``go install golang.org/x/vuln/cmd/govulncheck@latest``,

Index: docs/development/20210916194900.zettel
==================================================================
--- docs/development/20210916194900.zettel
+++ docs/development/20210916194900.zettel
@@ -1,10 +1,11 @@
 id: 20210916194900
 title: Checklist for Release
 role: zettel
 syntax: zmk
-modified: 20220309105459
+created: 20210916194900
+modified: 20230402181229
 
 # Sync with the official repository
 #* ``fossil sync -u``
 # Make sure that there is no workspace defined.
 #* ``ls ..`` must not have a file ''go.work'', in no parent folder.
@@ -47,12 +48,12 @@
 # Create the release:
 #* ``go run tools/build.go release`` (alternatively: ``make release``).
 # Remove previous executables:
 #* ``fossil uv remove --glob '*-PREVVERSION*'``
 # Add executables for release:
-#* ``cd release``
+#* ``cd releases``
 #* ``fossil uv add *.zip``
 #* ``cd ..``
 #* Synchronize with main repository:
 #* ``fossil sync -u``
 # Enable autosync:
 #* ``fossil setting autosync on``

Index: docs/manual/00001004051200.zettel
==================================================================
--- docs/manual/00001004051200.zettel
+++ docs/manual/00001004051200.zettel
@@ -15,16 +15,16 @@
 ; ''-t FORMAT''
 : Specifies the output format.
   Supported values are:
   [[''html''|00001012920510]] (default),
   [[''md''|00001012920513]],
-  [[''sexpr''|00001012920516]],
   [[''shtml''|00001012920525]],
+  [[''sz''|00001012920516]],
   [[''text''|00001012920519]],
   and [[''zmk''|00001012920522]].
 ; ''file-1''
 : Specifies the file name, where at least metadata is read.
   If ''file-2'' is not given, the zettel content is also read from here.
 ; ''file-2''
 : File name where the zettel content is stored.
 
 If neither ''file-1'' nor ''file-2'' are given, metadata and zettel content are read from standard input / stdin.

Index: docs/manual/00001006000000.zettel
==================================================================
--- docs/manual/00001006000000.zettel
+++ docs/manual/00001006000000.zettel
@@ -2,11 +2,11 @@
 title: Layout of a Zettel
 role: manual
 tags: #design #manual #zettelstore
 syntax: zmk
 created: 20210126175322
-modified: 20221219162703
+modified: 20230403123541
 
 A zettel consists of two parts: the metadata and the zettel content.
 Metadata gives some information mostly about the zettel content, how it should be interpreted, how it is sorted within Zettelstore.
 The zettel content is, well, the actual content.
 In many cases, the content is in plain text form.
@@ -30,14 +30,14 @@
 And there is support for some binary image formats, like GIF, PNG, and JPEG.
 
 === Plain, parsed, and evaluated zettel
 Zettelstore may present your zettel in various forms, typically retrieved with the [[endpoint|00001012920000]] ''/z/{ID}''.
 One way is to present the zettel as it was read by Zettelstore.
-This is called ""[[plain zettel|00001003000000]]"".
+This is called ""[[plain zettel|00001012053300]]"".
 
 The second way is to present the zettel as it was recognized by Zettelstore.
-This is called ""[[parsed zettel|00001012053600]]"", also retrieved with the [[endpoint|00001012920000]] ''/z/{ID}'', but with additional query parameter.
+This is called ""[[parsed zettel|00001012053600]]"", also retrieved with the [[endpoint|00001012920000]] ''/z/{ID}'', but with the additional query parameter ''parseonly''.
 Such a zettel was read and analyzed.
 It can be presented in various [[encodings|00001012920500]].[^The [[zmk encoding|00001012920522]] allows you to compare the plain, the parsed, and the evaluated form of a zettel.]
 
 However, a zettel such as this one you are currently reading, is a ""[[evaluated zettel|00001012053500]]"", also retrieved with the [[endpoint|00001012920000]] ''/z/{ID}'' and specifying an encoding.
 The biggest difference to a parsed zettel is the inclusion of [[block transclusions|00001007031100]] or [[inline transclusions|00001007040324]] for an evaluated zettel.

Index: docs/manual/00001006020000.zettel
==================================================================
--- docs/manual/00001006020000.zettel
+++ docs/manual/00001006020000.zettel
@@ -2,11 +2,11 @@
 title: Supported Metadata Keys
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210126175322
-modified: 20230320150950
+modified: 20230421155051
 
 Although you are free to define your own metadata, by using any key (according to the [[syntax|00001006010000]]), some keys have a special meaning that is enforced by Zettelstore.
 See the [[computed list of supported metadata keys|00000000000090]] for details.
 
 Most keys conform to a [[type|00001006030000]].
@@ -42,10 +42,17 @@
   It is internally created by hashing the password, the [[zettel identifier|00001006050000]], and the value of the ''ident'' key.
 
   It is only used for zettel with a ''role'' value of ""user"".
 ; [!dead|''dead'']
 : Property that contains all references that does __not__ identify a zettel.
+; [!expire|''expire'']
+: A user-entered time stamp that document the point in time when the zettel should expire.
+  When a zettel is expires, Zettelstore does nothing.
+  It is up to you to define required actions.
+  ''expire'' is just a documentation.
+  You could define a query and execute it regularly, for example [[query:expire? ORDER expire]].
+  Alternatively, a Zettelstore client software could define some actions when it detects expired zettel.
 ; [!folge|''folge'']
 : Is a property that contains identifier of all zettel that reference this zettel through the [[''precursor''|#precursor]] value.
 ; [!forward|''forward'']
 : Property that contains all references that identify another zettel within the content of the zettel.
 ; [!id|''id'']
@@ -94,19 +101,24 @@
 ; [!role|''role'']
 : Defines the role of the zettel.
   Can be used for selecting zettel.
   See [[supported zettel roles|00001006020100]].
   If not given, it is ignored.
+; [!subordinates|''subordinates'']
+: Is a property that contains identifier of all zettel that reference this zettel through the [[''superior''|#superior]] value.
 ; [!successors|''successors'']
 : Is a property that contains identifier of all zettel that reference this zettel through the [[''predecessor''|#predecessor]] value.
   Therefore, it references all zettel that contain a new version of the content and/or metadata.
   In contrast to [[''folge''|#folge]], these are references because of technical reasons, not because of content-related reasons.
   In most cases, zettel referencing the current zettel should be updated to reference a successor zettel.
   The [[query reference|00001007040310]] [[query:backward? successors?]] lists all such zettel.
 ; [!summary|''summary'']
 : Summarizes the content of the zettel.
   You may use all [[inline-structued elements|00001007040000]] of Zettelmarkup.
+; [!superior|''superior'']
+: Specifies a zettel that is conceptually a superior zettel.
+  This might be a more abstract zettel, or a zettel that should be higher in a hierarchy.
 ; [!syntax|''syntax'']
 : Specifies the syntax that should be used for interpreting the zettel.
   The zettel about [[other markup languages|00001008000000]] defines supported values.
   If it is not given, it defaults to ''plain''.
 ; [!tags|''tags'']

Index: docs/manual/00001006030000.zettel
==================================================================
--- docs/manual/00001006030000.zettel
+++ docs/manual/00001006030000.zettel
@@ -1,20 +1,23 @@
 id: 00001006030000
 title: Supported Key Types
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
-modified: 20220304114106
+created: 20210126175322
+modified: 20230402183536
 
 All [[supported metadata keys|00001006020000]] conform to a type.
 
 User-defined metadata keys conform also to a type, based on the suffix of the key.
 
 |=Suffix|Type
+| ''-date'' | [[Timestamp|00001006034500]]
 | ''-number'' | [[Number|00001006033000]]
 | ''-role'' | [[Word|00001006035500]]
 | ''-set'' | [[WordSet|00001006036000]]
+| ''-time'' | [[Timestamp|00001006034500]]
 | ''-title'' | [[Zettelmarkup|00001006036500]]
 | ''-url'' | [[URL|00001006035000]]
 | ''-zettel''  | [[Identifier|00001006032000]]
 | ''-zid''  | [[Identifier|00001006032000]]
 | ''-zids''  | [[IdentifierSet|00001006032500]]

Index: docs/manual/00001006031000.zettel
==================================================================
--- docs/manual/00001006031000.zettel
+++ docs/manual/00001006031000.zettel
@@ -2,19 +2,19 @@
 title: Credential Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914130324
+modified: 20230419175515
 
 Values of this type denote a credential value, e.g. an encrypted password.
 
 === Allowed values
 All printable characters are allowed.
 Since a credential contains some kind of secret, the sequence of characters might have some hidden syntax to be interpreted by other parts of Zettelstore.
 
-=== Query operators
+=== Query comparison
 A credential never compares to any other value.
 A comparison will never match in any way.
 
 === Sorting
 If a list of zettel should be sorted based on a credential value, the identifier of the respective zettel is used instead.

Index: docs/manual/00001006031500.zettel
==================================================================
--- docs/manual/00001006031500.zettel
+++ docs/manual/00001006031500.zettel
@@ -2,24 +2,24 @@
 title: EString Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914130448
+modified: 20230419175525
 
 Values of this type are just a sequence of character, possibly an empty sequence.
 
 An EString is the most general metadata key type, as it places no restrictions to the character sequence.[^Well, there are some minor restrictions that follow from the [[metadata syntax|00001006010000]].]
 
 === Allowed values
 All printable characters are allowed.
 
-=== Query operator
+=== Query comparison
 All comparisons are done case-insensitive, i.e. ""hell"" will be the prefix of ""Hello"".
 
 === Sorting
 To sort two values, the underlying encoding is used to determine which value is less than the other.
 
 Uppercase letters are typically interpreted as less than their corresponding lowercase letters, i.e. ``A < a``.
 
 Comparison is done character-wise by finding the first difference in the respective character sequence.
 For example, ``abc > aBc``.

Index: docs/manual/00001006032000.zettel
==================================================================
--- docs/manual/00001006032000.zettel
+++ docs/manual/00001006032000.zettel
@@ -2,20 +2,20 @@
 title: Identifier Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914134914
+modified: 20230419175535
 
 Values of this type denote a [[zettel identifier|00001006050000]].
 
 === Allowed values
 Must be a sequence of 14 digits (""0""--""9"").
 
-=== Query operator
+=== Query comparison
 Comparison is done with the string representation of the identifiers.
 For example, ""000010"" matches ""[[00001006032000]]"".
 
 === Sorting
 Sorting is done by comparing the [[String|00001006033500]] values.
 
 If both values are identifiers, this works well because both have the same length.

Index: docs/manual/00001006032500.zettel
==================================================================
--- docs/manual/00001006032500.zettel
+++ docs/manual/00001006032500.zettel
@@ -2,21 +2,21 @@
 title: IdentifierSet Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914131354
+modified: 20230419175551
 
 Values of this type denote a (sorted) set of [[zettel identifier|00001006050000]].
 
 A set is different to a list, as no duplicate values are allowed.
 
 === Allowed values
 Must be at least one sequence of 14 digits (""0""--""9""), separated by space characters.
 
-=== Query operator
+=== Query comparison
 A value matches an identifier set value, if the value matches any of the identifier set values.
 
 For example, ""000010060325"" is a prefix ""[[00001006032000]] [[00001006032500]]"".
 
 === Sorting
 Sorting is done by comparing the [[String|00001006033500]] values.

Index: docs/manual/00001006033000.zettel
==================================================================
--- docs/manual/00001006033000.zettel
+++ docs/manual/00001006033000.zettel
@@ -2,17 +2,17 @@
 title: Number Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914131211
+modified: 20230419175623
 
 Values of this type denote a numeric integer value.
 
 === Allowed values
 Must be a sequence of digits (""0""--""9""), optionally prefixed with a ""-"" or a ""+"" character.
 
-=== Query operator
-All comparisons are done on the given string representation of the number, ""+12"" will be treated as a different number of ""12"".
+=== Query comparison
+All comparisons are done on the given string representation of the number, ""+12"" will be treated as a different number ""12"".
 
 === Sorting
 Sorting is done by comparing the numeric values.

Index: docs/manual/00001006033500.zettel
==================================================================
--- docs/manual/00001006033500.zettel
+++ docs/manual/00001006033500.zettel
@@ -2,23 +2,23 @@
 title: String Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914130505
+modified: 20230419175633
 
 Values of this type are just a sequence of character, but not an empty sequence.
 
 === Allowed values
 All printable characters are allowed.
 There must be at least one such character.
 
-=== Query operator
+=== Query comparison
 All comparisons are done case-insensitive, i.e. ""hell"" will be the prefix of ""Hello"".
 
 === Sorting
 To sort two values, the underlying encoding is used to determine which value is less than the other.
 
 Uppercase letters are typically interpreted as less than their corresponding lowercase letters, i.e. ``A < a``.
 
 Comparison is done character-wise by finding the first difference in the respective character sequence.
 For example, ``abc > aBc``.

Index: docs/manual/00001006034000.zettel
==================================================================
--- docs/manual/00001006034000.zettel
+++ docs/manual/00001006034000.zettel
@@ -2,11 +2,11 @@
 title: TagSet Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914131048
+modified: 20230419175642
 
 Values of this type denote a (sorted) set of tags.
 
 A set is different to a list, as no duplicate values are allowed.
 
@@ -14,10 +14,10 @@
 Every tag must must begin with the number sign character (""''#''"", U+0023), followed by at least one printable character.
 Tags are separated by space characters.
 
 All characters are mapped to their lower case values.
 
-=== Query operator
+=== Query comparison
 All comparisons are done case-sensitive, i.e. ""#hell"" will not be the prefix of ""#Hello"".
 
 === Sorting
 Sorting is done by comparing the [[String|00001006033500]] values.

Index: docs/manual/00001006034500.zettel
==================================================================
--- docs/manual/00001006034500.zettel
+++ docs/manual/00001006034500.zettel
@@ -2,11 +2,11 @@
 title: Timestamp Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914130919
+modified: 20230419175713
 
 Values of this type denote a point in time.
 
 === Allowed values
 Must be a sequence of 14 digits (""0""--""9"") (same as an [[Identifier|00001006032000]]), with the restriction that is conforms to the pattern ""YYYYMMDDhhmmss"".
@@ -16,12 +16,13 @@
 * DD is the day,
 * hh is the hour,
 * mm is the minute,
 * ss is the second.
 
-=== Query operator
+=== Query comparison
 All comparisons assume that up to 14 digits are given.
+Comparison is done through the string representation.
 
 === Sorting
 Sorting is done by comparing the [[String|00001006033500]] values.
 
 If both values are timestamp values, this works well because both have the same length.

Index: docs/manual/00001006035000.zettel
==================================================================
--- docs/manual/00001006035000.zettel
+++ docs/manual/00001006035000.zettel
@@ -2,18 +2,18 @@
 title: URL Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914130809
+modified: 20230419175725
 
 Values of this type denote an URL.
 
 === Allowed values
 All characters of an URL / URI are allowed.
 
-=== Query operator
+=== Query comparison
 All comparisons are done case-insensitive.
 For example, ""hello"" is the suffix of ""http://example.com/Hello"".
 
 === Sorting
 Sorting is done by comparing the [[String|00001006033500]] values.

Index: docs/manual/00001006035500.zettel
==================================================================
--- docs/manual/00001006035500.zettel
+++ docs/manual/00001006035500.zettel
@@ -2,19 +2,19 @@
 title: Word Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914130655
+modified: 20230419175735
 
 Values of this type denote a single word.
 
 === Allowed values
 Must be a non-empty sequence of characters, but without the space character.
 
 All characters are mapped to their lower case values.
 
-=== Query operator
+=== Query comparison
 All comparisons are done case-insensitive, i.e. ""hell"" will be the prefix of ""Hello"".
 
 === Sorting
 Sorting is done by comparing the [[String|00001006033500]] values.

Index: docs/manual/00001006036000.zettel
==================================================================
--- docs/manual/00001006036000.zettel
+++ docs/manual/00001006036000.zettel
@@ -2,19 +2,19 @@
 title: WordSet Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914130725
+modified: 20230419175745
 
 Values of this type denote a (sorted) set of [[words|00001006035500]].
 
 A set is different to a list, as no duplicate values are allowed.
 
 === Allowed values
 Must be a sequence of at least one word, separated by space characters.
 
-=== Query operator
+=== Query comparison
 All comparisons are done case-insensitive, i.e. ""hell"" will be the prefix of ""World, Hello"".
 
 === Sorting
 Sorting is done by comparing the [[String|00001006033500]] values.

Index: docs/manual/00001006036500.zettel
==================================================================
--- docs/manual/00001006036500.zettel
+++ docs/manual/00001006036500.zettel
@@ -2,19 +2,19 @@
 title: Zettelmarkup Key Type
 role: manual
 tags: #manual #meta #reference #zettel #zettelstore
 syntax: zmk
 created: 20210212135017
-modified: 20220914135405
+modified: 20230419175441
 
 Values of this type are [[String|00001006033500]] values, interpreted as [[Zettelmarkup|00001007000000]].
 
 === Allowed values
 All printable characters are allowed.
 There must be at least one such character.
 
-=== Query operator
+=== Query comparison
 Comparison is done similar to the full-text search: both the value to compare and the metadata value are normalized according to Unicode NKFD, ignoring everything except letters and numbers.
 Letters are mapped to the corresponding lower-case value.
 
 For example, ""Brücke"" will be the prefix of ""(Bruckenpfeiler,"".
 

Index: docs/manual/00001007031300.zettel
==================================================================
--- docs/manual/00001007031300.zettel
+++ docs/manual/00001007031300.zettel
@@ -12,11 +12,11 @@
 You can add some [[attributes|00001007050000]] on the beginning line of a verbatim block, following the initiating characters.
 The evaluation block supports the default attribute[^Depending on the syntax value.]: when given, all spaces in the text are rendered in HTML as open box characters (U+2423).
 If you want to give only one attribute and this attribute is the generic attribute, you can omit the most of the attribute syntax and just specify the value.
 It will be interpreted as a [[syntax|00001008000000]] value to evaluate its content.
 Not all syntax values are supported by Zettelstore.[^Currently just ""[[draw|00001008050000]]"".]
-The main reason for an evaluation block is to be used with external software via the [[Sexpr encoding|00001012920516]].
+The main reason for an evaluation block is to be used with external software via the [[sz encoding|00001012920516]].
 
 Any other character in this line will be ignored
 
 Text following the beginning line will not be interpreted, until a line begins with at least the same number of the same characters given at the beginning line.
 This allows to enter some tilde characters in the text that should not be interpreted.

Index: docs/manual/00001007031400.zettel
==================================================================
--- docs/manual/00001007031400.zettel
+++ docs/manual/00001007031400.zettel
@@ -14,11 +14,11 @@
 A math-mode block supports the default attribute[^Depending on the syntax value.]: when given, all spaces in the text are rendered in HTML as open box characters (U+2423).
 If you want to give only one attribute and this attribute is the generic attribute, you can omit the most of the attribute syntax and just specify the value.
 It will be interpreted as a [[syntax|00001008000000]] value to evaluate its content.
 Alternatively, you could provide an attribute with the key ""syntax"" and use the value to specify the syntax.
 Not all syntax values are supported by Zettelstore.[^Currently: none.]
-External software might support several values via the [[Sexpr encoding|00001012920516]].
+External software might support several values via the [[sz encoding|00001012920516]].
 
 Any other character in this line will be ignored
 
 Text following the beginning line will not be interpreted, until a line begins with at least the same number of the same characters given at the beginning line.
 This allows to enter some dollar-sign characters in the text that should not be interpreted.

Index: docs/manual/00001007700000.zettel
==================================================================
--- docs/manual/00001007700000.zettel
+++ docs/manual/00001007700000.zettel
@@ -2,20 +2,43 @@
 title: Query expression
 role: manual
 tags: #manual #search #zettelstore
 syntax: zmk
 created: 20220805150154
-modified: 20220913135434
+modified: 20230420190257
 
 A query expression allows you to search for specific zettel and to perform some actions on them.
 You may select zettel based on a full-text search, based on specific metadata values, or both.
 
-A query expression consists of a __search expression__ and of an optional __action list__.
-Both are separated by a vertical bar character (""''|''"", U+007C).
+A query expression consists of an optional __context expression__, a __search expression__ and an optional __action list__.
+The latter two are separated by a vertical bar character (""''|''"", U+007C).
 
 A query expression follows a [[formal syntax|00001007780000]].
 
+=== Context expression
+
+An context expression starts with the keyword ''CONTEXT'', one or more space characters, and a [[zettel identifier|00001006050000]].
+
+Optionally you may specify some context details, separated by space character. These are:
+* ''BACKWARD'': search for context only though backward links,
+* ''FORWARD'': search for context only through forward links,
+* ''COST'', one or more space characters, and a positive integer: set the maximum __cost__ (default: 17),
+* ''MAX'', one or more space characters, and a positive integer: set the maximum number of context zettel (default: 200).
+
+If no ''BACKWARD'' and ''FORWARD'' is specified, a search for context zettel will be done though backward and forward links.
+
+The cost of a context zettel is calculated iteratively:
+* The specified zettel hast a cost of one.
+* A zettel found as a single folge zettel or single precursor zettel has the cost of the originating zettel, plus one.
+* A zettel found as a single successor zettel or single predecessor zettel has the cost of the originating zettel, plus two.
+* A zettel found via another link without being part of a [[set of zettel identifier|00001006032500]], has the cost of the originating zettel, plus three.
+* A zettel which is part of a set of zettel identifier, has the cost of the originating zettel, plus one of the three choices above and multiplied with roughly a logarithmic value based on the size of the set.
+* A zettel with the same tag, has the cost of the originating zettel, plus the number of zettel with the same tag (if it is less than eight), or the cost of the originating zettel plus two, multiplied by number of zettel with the same tag divided by four.
+
+Despite its possibly complicated structure, this algorithm ensures in practice that the zettel context is a list of zettel, where the first elements are ""near"" to the specified zettel and the last elements are more ""distant"" to the specified zettel.
+It also penalties a zettel that acts as a ""hub"" to other zettel, to make it more likely that only relevant zettel appear on the context list.
+
 === Search expression
 
 In its simplest form, a search expression just contains a string to be search for with the help of a full-text search.
 For example, the string ''syntax'' will search for all zettel containing the word ""syntax"".
 
@@ -30,11 +53,11 @@
 
 * [[Search terms|00001007702000]]
 * [[Search operator|00001007705000]]
 * [[Search value|00001007706000]]
 
-Here are [[some examples|00001007790000]] of search expressions, which can be used to manage a Zettelstore:
+Here are [[some examples|00001007790000]] of search / context expressions, which can be used to manage a Zettelstore:
 {{{00001007790000}}}
 
 === Action List
 
 With a search expression, a list of zettel is selected.

Index: docs/manual/00001007702000.zettel
==================================================================
--- docs/manual/00001007702000.zettel
+++ docs/manual/00001007702000.zettel
@@ -2,11 +2,11 @@
 title: Search term
 role: manual
 tags: #manual #search #zettelstore
 syntax: zmk
 created: 20220805150154
-modified: 20230327123724
+modified: 20230420153154
 
 A search term allows you to specify one search restriction.
 The result [[search expression|00001007700000]], which contains more than one search term, will be the applications of all restrictions.
 
 A search term can be one of the following (the first three term are collectively called __search literals__):
@@ -32,11 +32,11 @@
   Any search expression will be in a [[disjunctive normal form|https://en.wikipedia.org/wiki/Disjunctive_normal_form]].
 
   It has no effect on the following search terms initiated with a special uppercase word.
 * The string ''PICK'', followed by a non-empty sequence of spaces and a number greater zero (called ""N"").
 
-  This will pick randomly N elements of the result list.
+  This will pick randomly N elements of the result list, preserving the order of that list.
   A zero value of N will produce the same result as if nothing was specified.
   If specified multiple times, the lower value takes precedence.
 
   Example: ''PICK 5 PICK 3'' will be interpreted as ''PICK 3''.
 * The string ''ORDER'', followed by a non-empty sequence of spaces and the name of a metadata key, will specify an ordering of the result list.
@@ -57,13 +57,13 @@
 * The string ''RANDOM'' will provide a random order of the resulting list.
 
   Currently, only the first term specifying the order of the resulting list will be used.
   Other ordering terms will be ignored.
 
-  A random order specification will be ignored, if there is an explicit ordering given or if the specification contains a valid ''PICK''.
+  A random order specification will be ignored, if there is an explicit ordering given.
 
-  Example: ''RANDOM ORDER published'' will be interpreted as ''ORDER published'', ''PICK 3 RANDOM'' will be interpreted as ''PICK 3''.
+  Example: ''RANDOM ORDER published'' will be interpreted as ''ORDER published''.
 * The string ''OFFSET'', followed by a non-empty sequence of spaces and a number greater zero (called ""N"").
 
   This will ignore the first N elements of the result list, based on the specified sort order.
   A zero value of N will produce the same result as if nothing was specified.
   If specified multiple times, the higher value takes precedence.
@@ -83,10 +83,6 @@
 * The first search operator character found in a search term divides the term into two pieces.
   If the first piece, from the beginning of the search term to the search operator character, is syntactically a metadata key, the search term is treated as a metadata-based search.
 * Otherwise, the search term is treated as a full-text search.
 
 If a term like ''PICK'', ''ORDER'', ''ORDER REVERSE'', ''OFFSET'', or ''LIMIT'' is not followed by an appropriate value, it is interpreted as a search value for a full-text search.
-For example, ''ORDER 123'' will search for a zettel conatining the strings ""ORDER"" (case-insensitive) and ""123"".
-
-A specification ''RANDOM LIMIT n'' (with some valid value of ''n'') will be interpreted as ''PICK n''.
-Similar, a specification ''PICK n'', where ''n'' is greater or equal to the length of the result list, will be interpreted as ''RANDOM''.
-A specification ''LIMIT n'', where ''n'' is greater or equal to the length of the result list, will be ignored effectively.
+For example, ''ORDER 123'' will search for a zettel containing the strings ""ORDER"" (case-insensitive) and ""123"".

Index: docs/manual/00001007705000.zettel
==================================================================
--- docs/manual/00001007705000.zettel
+++ docs/manual/00001007705000.zettel
@@ -1,32 +1,37 @@
 id: 00001007705000
 title: Search operator
 role: manual
 tags: #manual #search #zettelstore
 syntax: zmk
-modified: 20220819194709
+created: 20220805150154
+modified: 20230419163812
 
 A search operator specifies how the comparison of a search value and a zettel should be executed.
 Every comparison is done case-insensitive, treating all uppercase letters the same as lowercase letters.
 
 The following are allowed search operator characters:
-* The exclamation mark character (""!"", U+0021) negates the meaning
+* The exclamation mark character (""''!''"", U+0021) negates the meaning
+* The equal sign character (""'' ''"", U+003D) compares on equal content (""equals operator"")
 * The tilde character (""''~''"", U+007E) compares on matching (""match operator"")
 * The greater-than sign character (""''>''"", U+003E) matches if there is some prefix (""prefix operator"")
 * The less-than sign character (""''<''"", U+003C) compares a suffix relationship (""suffix operator"")
-* The colon character (""'':''"", U+003A) compares on equal words (""has operator"")
+* The colon character (""'':''"", U+003A) compares depending on the on the actual [[key type|00001006030000]] (""has operator"").
+  In most cases, it acts as a equals operator, but for some type it acts as the match operator.
 * The question mark (""''?''"", U+003F) checks for an existing metadata key (""exist operator"")
 
-Since the exclamation mark character can be combined with the other, there are 10 possible combinations:
+Since the exclamation mark character can be combined with the other, there are 14 possible combinations:
 # ""''!''"": is an abbreviation of the ""''!~''"" operator.
 # ""''~''"": is successful if the search value matched the value to be compared.
 # ""''!~''"": is successful if the search value does not match the value to be compared.
-# ""'':''"": is successful if the search value is equal to one word of the value to be compared.
-# ""''!:''"": is successful if the search value is not equal to any word of the value to be compared.
+# ""''=''"": is successful if the search value is equal to one word of the value to be compared.
+# ""''!=''"": is successful if the search value is not equal to any word of the value to be compared.
 # ""''>''"": is successful if the search value is a prefix of the value to be compared.
 # ""''!>''"": is successful if the search value is not a prefix of the value to be compared.
 # ""''<''"": is successful if the search value is a suffix of the value to be compared.
 # ""''!<''"": is successful if the search value is not a suffix of the value to be compared.
+# ""'':''"": is successful if the search value is has/match one word of the value to be compared.
+# ""''!:''"": is successful if the search value is not match/has to any word of the value to be compared.
 # ""''?''"": is successful if the metadata contains the given key.
 # ""''!?''"": is successful if the metadata does not contain the given key.
 # ""''''"": a missing search operator can only occur for a full-text search.
   It is equal to the ""''~''"" operator.

Index: docs/manual/00001007780000.zettel
==================================================================
--- docs/manual/00001007780000.zettel
+++ docs/manual/00001007780000.zettel
@@ -2,30 +2,35 @@
 title: Formal syntax of query expressions
 role: manual
 tags: #manual #reference #search #zettelstore
 syntax: zmk
 created: 20220810144539
-modified: 20230327122634
+modified: 20230411162000
 
 ```
-QueryExpression  := SearchExpression ActionExpression?
-SearchExpression := SearchTerm (SPACE+ SearchTerm)*.
-SearchTerm       := SearchOperator? SearchValue
-                  | SearchKey SearchOperator SearchValue?
-                  | SearchKey ExistOperator
-                  | "OR"
-                  | "RANDOM"
-                  | "PICK" SPACE+ PosInt
-                  | "ORDER" SPACE+ ("REVERSE" SPACE+)? SearchKey
-                  | "OFFSET" SPACE+ PosInt
-                  | "LIMIT" SPACE+ PosInt.
-SearchValue      := Word.
-SearchKey        := MetadataKey.
-SearchOperator   := '!'
-                  | ('!')? ('~' | ':' | '<' | '>').
-ExistOperator    := '?'
-                  | '!' '?'.
-PosInt           := '0'
-                  | ('1' .. '9') DIGIT*.
-ActionExpression := '|' (Word (SPACE+ Word)*)?
-Word             := NO-SPACE NO-SPACE*
+QueryExpression   := ContextExpression? SearchExpression ActionExpression?
+ContextExpression := "CONTEXT" SPACE+ ZID (SPACE+ ContextDetail)*.
+ContextDetail     := "BACKWARD"
+                   | "FORWARD"
+                   | "COST" SPACE+ PosInt
+                   | "MAX" SPACE+ PosInt.
+SearchExpression  := SearchTerm (SPACE+ SearchTerm)*.
+SearchTerm        := SearchOperator? SearchValue
+                   | SearchKey SearchOperator SearchValue?
+                   | SearchKey ExistOperator
+                   | "OR"
+                   | "RANDOM"
+                   | "PICK" SPACE+ PosInt
+                   | "ORDER" SPACE+ ("REVERSE" SPACE+)? SearchKey
+                   | "OFFSET" SPACE+ PosInt
+                   | "LIMIT" SPACE+ PosInt.
+SearchValue       := Word.
+SearchKey         := MetadataKey.
+SearchOperator    := '!'
+                   | ('!')? ('~' | ':' | '<' | '>').
+ExistOperator     := '?'
+                   | '!' '?'.
+PosInt            := '0'
+                   | ('1' .. '9') DIGIT*.
+ActionExpression  := '|' (Word (SPACE+ Word)*)?
+Word              := NO-SPACE NO-SPACE*
 ```

Index: docs/manual/00001007790000.zettel
==================================================================
--- docs/manual/00001007790000.zettel
+++ docs/manual/00001007790000.zettel
@@ -2,15 +2,17 @@
 title: Useful query expressions
 role: manual
 tags: #example #manual #search #zettelstore
 syntax: zmk
 created: 20220810144539
-modified: 20230327122547
+modified: 20230420153334
 
 |= Query Expression |= Meaning
 | [[query:role:configuration]] | Zettel that contains some configuration data for the Zettelstore
 | [[query:ORDER REVERSE created LIMIT 40]] | 40 recently created zettel
 | [[query:ORDER REVERSE published LIMIT 40]] | 40 recently updated zettel
-| [[query:PICK 40]] | 40 random zettel
+| [[query:PICK 40]] | 40 random zettel, ordered by zettel identifier
 | [[query:dead?]] | Zettel with invalid / dead links
 | [[query:backward!? precursor!?]] | Zettel that are not referenced by other zettel
 | [[query:tags!?]] | Zettel without tags
+| [[query:expire? ORDER expire]] | Zettel with an expire date, ordered from the nearest to the latest
+| [[query:CONTEXT 00001007700000]] | Zettel within the context of the [[given zettel|00001007700000]]

Index: docs/manual/00001008050000.zettel
==================================================================
--- docs/manual/00001008050000.zettel
+++ docs/manual/00001008050000.zettel
@@ -1,11 +1,12 @@
 id: 00001008050000
-title: The ""draw"" language
+title: The "draw" language
 role: manual
 tags: #graphic #manual #zettelstore
 syntax: zmk
-modified: 20220311120439
+created: 20220131142036
+modified: 20230403123738
 
 Sometimes, ""a picture is worth a thousand words"".
 To create some graphical representations, Zettelmarkup provides a simple mechanism.
 Characters like ""''|''"" or ""''-''"" already provide some visual feedback.
 For example, to create a picture containing two boxes that are connected via an arrow, the following representation is possible:

Index: docs/manual/00001012000000.zettel
==================================================================
--- docs/manual/00001012000000.zettel
+++ docs/manual/00001012000000.zettel
@@ -2,11 +2,11 @@
 title: API
 role: manual
 tags: #api #manual #zettelstore
 syntax: zmk
 created: 20210126175322
-modified: 20221219150243
+modified: 20230411164103
 
 The API (short for ""**A**pplication **P**rogramming **I**nterface"") is the primary way to communicate with a running Zettelstore.
 Most integration with other systems and services is done through the API.
 The [[web user interface|00001014000000]] is just an alternative, secondary way of interacting with a Zettelstore.
 
@@ -29,11 +29,10 @@
 * [[Create a new zettel|00001012053200]]
 * [[Retrieve metadata and content of an existing zettel|00001012053300]]
 * [[Retrieve metadata of an existing zettel|00001012053400]]
 * [[Retrieve evaluated metadata and content of an existing zettel in various encodings|00001012053500]]
 * [[Retrieve parsed metadata and content of an existing zettel in various encodings|00001012053600]]
-* [[Retrieve context of an existing zettel|00001012053800]]
 * [[Retrieve unlinked references to an existing zettel|00001012053900]]
 * [[Retrieve zettel order within an existing zettel|00001012054000]]
 * [[Update metadata and content of a zettel|00001012054200]]
 * [[Rename a zettel|00001012054400]]
 * [[Delete a zettel|00001012054600]]

Index: docs/manual/00001012050200.zettel
==================================================================
--- docs/manual/00001012050200.zettel
+++ docs/manual/00001012050200.zettel
@@ -1,51 +1,52 @@
 id: 00001012050200
 title: API: Authenticate a client
 role: manual
 tags: #api #manual #zettelstore
 syntax: zmk
-modified: 20220107215844
+created: 20210126175322
+modified: 20230412150544
 
 Authentication for future API calls is done by sending a [[user identification|00001010040200]] and a password to the Zettelstore to obtain an [[access token|00001010040700]].
 This token has to be used for other API calls.
 It is valid for a relatively short amount of time, as configured with the key ''token-lifetime-api'' of the [[startup configuration|00001004010000#token-lifetime-api]] (typically 10 minutes).
 
 The simplest way is to send user identification (''IDENT'') and password (''PASSWORD'') via [[HTTP Basic Authentication|https://tools.ietf.org/html/rfc7617]] and send them to the [[endpoint|00001012920000]] ''/a'' with a POST request:
 ```sh
 # curl -X POST -u IDENT:PASSWORD http://127.0.0.1:23123/a
-{"access_token":"eyJhbGciOiJIUzUxMiJ9.eyJfdGsiOjEsImV4cCI6MTYwMTczMTI3NSwiaWF0IjoxNjAxNzMwNjc1LCJzdWIiOiJhYmMiLCJ6aWQiOiIyMDIwMTAwMzE1MDEwMCJ9.ekhXkvn146P2bMKFQcU-bNlvgbeO6sS39hs6U5EKfjIqnSInkuHYjYAIfUqf_clYRfr6YBlX5izii8XfxV8jhg","token_type":"Bearer","expires_in":600}
+("Bearer" "eyJhbGciOiJIUzUxMiJ9.eyJfdGsiOjEsImV4cCI6MTY4MTMwNDA2MiwiaWF0IjoxNjgxMzA0MDAyLCJzdWIiOiJvd25lciIsInppZCI6IjIwMjEwNjI5MTYzMzAwIn0.kdF8PdiL50gIPkRD3ovgR6nUXR0-80EKAXcY2zVYgYvryF09iXnNR3zrvYnGzdrArMcnvAYqVvuXtqhQj2jG9g" 600)
 ```
 
 Some tools, like [[curl|https://curl.haxx.se/]], also allow to specify user identification and password as part of the URL:
 ```sh
 # curl -X POST http://IDENT:PASSWORD@127.0.0.1:23123/a
-{"access_token":"eyJhbGciOiJIUzUxMiJ9.eyJfdGsiOjEsImV4cCI6MTYwMTczMTI3NSwiaWF0IjoxNjAxNzMwNjc1LCJzdWIiOiJhYmMiLCJ6aWQiOiIyMDIwMTAwMzE1MDEwMCJ9.ekhXkvn146P2bMKFQcU-bNlvgbeO6sS39hs6U5EKfjIqnSInkuHYjYAIfUqf_clYRfr6YBlX5izii8XfxV8jhg","token_type":"Bearer","expires_in":600}
+("Bearer" "eyJhbGciOiJIUzUxMiJ9.eyJfdGsiOjEsImV4cCI6MTY4MTMwNDA4NiwiaWF0IjoxNjgxMzA0MDI2LCJzdWIiOiJvd25lciIsInppZCI6IjIwMjEwNjI5MTYzMzAwIn0.kZd3prYc79dt9efDsrYVHtKrjWyOWvfByjeeUB3hf_vs43V3SNJqmb8k-zTHVNWOK0-5orVPrg2tIAqbXqmkhg" 600)
 ```
 
 If you do not want to use Basic Authentication, you can also send user identification and password as HTML form data:
 ```sh
 # curl -X POST -d 'username=IDENT&password=PASSWORD' http://127.0.0.1:23123/a
-{"access_token":"eyJhbGciOiJIUzUxMiJ9.eyJfdGsiOjEsImV4cCI6MTYwMTczMTI3NSwiaWF0IjoxNjAxNzMwNjc1LCJzdWIiOiJhYmMiLCJ6aWQiOiIyMDIwMTAwMzE1MDEwMCJ9.ekhXkvn146P2bMKFQcU-bNlvgbeO6sS39hs6U5EKfjIqnSInkuHYjYAIfUqf_clYRfr6YBlX5izii8XfxV8jhg","token_type":"Bearer","expires_in":600}
+("Bearer" "eyJhbGciOiJIUzUxMiJ9.eyJfdGsiOjEsImV4cCI6MTY4MTMwNDA4OCwiaWF0IjoxNjgxMzA0MDI4LCJzdWIiOiJvd25lciIsInppZCI6IjIwMjEwNjI5MTYzMzAwIn0.qIEyOMFXykCApWtBaqbSESwTL96stWl2LRICiRNAXUjcY-mwx_SSl9L5Fj2FvmrI1K1RBvWehjoq8KZUNjhJ9Q" 600)
 ```
 
-In all cases, you will receive an JSON object will all [[relevant data|00001012921000]] to be used for further API calls.
+In all cases, you will receive a list with three elements that will contain all [[relevant data|00001012921000]] to be used for further API calls.
 
 **Important:** obtaining a token is a time-intensive process.
 Zettelstore will delay every request to obtain a token for a certain amount of time.
 Please take into account that this request will take approximately 500 milliseconds, under certain circumstances more.
 
 However, if [[authentication is not enabled|00001010040100]] and you send an authentication request, no user identification/password checking is done and you receive an artificial token immediate, without any delay:
 
 ```sh
 # curl -X POST -u IDENT:PASSWORD http://127.0.0.1:23123/a
-{"token":"freeaccess","token_type":"Bearer","expires_in":316224000}
+("Bearer" "freeaccess" 316224000)
 ```
 
 In this case, it is even possible to omit the user identification/password.
 
 === HTTP Status codes
-In all cases of successful authentication, a JSON object is returned, which contains the token under the key ''"token"''.
+In all cases of successful authentication, a list is returned, which contains the token as the second element.
 A successful authentication is signaled with the HTTP status code 200, as usual.
 
 Other status codes possibly send by the Zettelstore:
 ; ''400''
 : Unable to process the request.

Index: docs/manual/00001012050400.zettel
==================================================================
--- docs/manual/00001012050400.zettel
+++ docs/manual/00001012050400.zettel
@@ -1,37 +1,38 @@
 id: 00001012050400
 title: API: Renew an access token
 role: manual
 tags: #api #manual #zettelstore
 syntax: zmk
-modified: 20220107215751
+created: 20210126175322
+modified: 20230412160219
 
 An access token is only valid for a certain duration.
 Since the [[authentication process|00001012050200]] will need some processing time, there is a way to renew the token without providing full authentication data.
 
 Send a HTTP PUT request to the [[endpoint|00001012920000]] ''/a'' and include the current access token in the ''Authorization'' header:
 
 ```sh
 # curl -X PUT -H 'Authorization: Bearer TOKEN' http://127.0.0.1:23123/a
-{"access_token":"eyJhbGciOiJIUzUxMiJ9.eyJfdGsiOjEsImV4cCI6MTYwMTczMTI3NSwiaWF0IjoxNjAxNzMwNjc1LCJzdWIiOiJhYmMiLCJ6aWQiOiIyMDIwMTAwMzE1MDEwMCJ9.ekhXkvn146P2bMKFQcU-bNlvgbeO6sS39hs6U5EKfjIqnSInkuHYjYAIfUqf_clYRfr6YBlX5izii8XfxV8jhg","token_type":"Bearer","expires_in":456}
+("Bearer" "eyJhbGciOiJIUzUxMiJ9.eyJfdGsiOjEsImV4cCI6MTY4MTMwNDA4NiwiaWF0IjoxNjgxMzA0MDI2LCJzdWIiOiJvd25lciIsInppZCI6IjIwMjEwNjI5MTYzMzAwIn0.kZd3prYc79dt9efDsrYVHtKrjWyOWvfByjeeUB3hf_vs43V3SNJqmb8k-zTHVNWOK0-5orVPrg2tIAqbXqmkhg" 456)
 ```
 You may receive a new access token, or the current one if it was obtained not a long time ago.
 However, the lifetime of the returned [[access token|00001012921000]] is accurate.
 
 If [[authentication is not enabled|00001010040100]] and you send a renew request, no checking is done and you receive an artificial token immediate, without any delay:
 
 ```sh
 # curl -X PUT -H 'Authorization: Bearer freeaccess' http://127.0.0.1:23123/a
-{"token":"freeaccess","token_type":"Bearer","expires_in":316224000}
+("Bearer" "freeaccess" 316224000)
 ```
 
 In this case, it is even possible to omit the access token.
 
 === HTTP Status codes
 ; ''200''
-: Renew process was successful, the body contains an [[appropriate JSON object|00001012921000]].
+: Renew process was successful, the body contains a [[list|00001012921000]] with the relevant data.
 ; ''400''
 : The renew process was not successful.
   There are several reasons for this.
   Maybe access bearer token was not valid.
 
   Probably you should [[authenticate|00001012050200]] again with user identification and password.

Index: docs/manual/00001012051200.zettel
==================================================================
--- docs/manual/00001012051200.zettel
+++ docs/manual/00001012051200.zettel
@@ -2,11 +2,11 @@
 title: API: List all zettel
 role: manual
 tags: #api #manual #zettelstore
 syntax: zmk
 created: 20210126175322
-modified: 20221219154400
+modified: 20230420160640
 
 To list all zettel just send a HTTP GET request to the [[endpoint|00001012920000]] ''/z''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header].
 Always use the endpoint ''/z'' to work with a list of zettel.
 
 Without further specifications, a plain text document is returned, with one line per zettel.
@@ -20,10 +20,14 @@
 00001012050600 API: Provide an access token
 00001012050400 API: Renew an access token
 00001012050200 API: Authenticate a client
 ...
 ```
+
+The list is **not** sorted, even in the these examples where it appears to be sorted.
+If you want to have it ordered, you must specify it with the help of a [[query expression|00001007700000]] / [[search term|00001007702000]].
+See [[Query the list of all zettel|00001012051400]] how to do it.
 
 Alternatively, you may retrieve the list of all zettel as a JSON object by specifying the encoding with the query parameter ''enc=json'':
 
 ```sh
 # curl 'http://127.0.0.1:23123/z?enc=json'
@@ -107,10 +111,12 @@
       "rights": 62
     }
   ]
 }
 ```
+
+Again, the list is typically **not** sorted, for example by the zettel identifier.
 
 The JSON object contains a key ''"list"'' where its value is a list of zettel JSON objects.
 These zettel JSON objects themselves contains the keys ''"id"'' (value is a string containing the [[zettel identifier|00001006050000]]), ''"meta"'' (value as a JSON object), and ''"rights"'' (encodes the [[access rights|00001012921200]] for the given zettel).
 The value of key ''"meta"'' effectively contains all metadata of the identified zettel, where metadata keys are encoded as JSON object keys and metadata values encoded as JSON strings.
 

Index: docs/manual/00001012051400.zettel
==================================================================
--- docs/manual/00001012051400.zettel
+++ docs/manual/00001012051400.zettel
@@ -2,11 +2,11 @@
 title: API: Query the list of all zettel
 role: manual
 tags: #api #manual #zettelstore
 syntax: zmk
 created: 20220912111111
-modified: 20230320151117
+modified: 20230420160857
 
 The [[endpoint|00001012920000]] ''/z'' also allows you to filter the list of all zettel[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header] and optionally to provide some actions.
 
 A [[query|00001007700000]] is an optional [[search expression|00001007700000#search-expression]], together with an optional [[list of actions|00001007700000#action-list]] (described below).
 An empty search expression will select all zettel.
@@ -20,22 +20,22 @@
 
 This parameter loosely resembles the search form of the [[web user interface|00001014000000]] or those of [[Zettelmarkup's Query Transclusion|00001007031140]].
 
 For example, if you want to retrieve all zettel that contain the string ""API"" in its title, your request will be:
 ```sh
-# curl 'http://127.0.0.1:23123/z?q=title%3AAPI'
+# curl 'http://127.0.0.1:23123/z?q=title%3AAPI+ORDER+REVERSE+id+OFFSET+1'
 00001012921000 API: JSON structure of an access token
 00001012920500 Formats available by the API
 00001012920000 Endpoints used by the API
 ...
 ```
 
 If you want to retrieve a JSON document:
 
 ```sh
-# curl 'http://127.0.0.1:23123/z?q=title%3AAPI&enc=json'
-{"query":"title:API","human":"title HAS API","list":[{"id":"00001012921200","meta":{"back":"00001012051200 00001012051400 00001012053300 00001012053400 00001012053800 00001012053900 00001012054000","backward":"00001012051200 00001012051400 00001012053300 00001012053400 00001012053800 00001012053900 00001012054000","box-number":"1","created":"00010101000000","forward":"00001003000000 00001006020400 00001010000000 00001010040100 00001010040200 00001010070200 00001010070300","modified":"20220201171959","published":"20220201171959","role":"manual","syntax":"zmk","tags":"#api #manual #reference #zettelstore","title":"API: Encoding of Zettel Access Rights"},"rights":62},{"id":"00001012921000","meta":{"back":"00001012050600 00001012051200","backward":"00001012050200 00001012050400 00001012050600 00001012051200","box-number":"1","created":"00010101000000","forward":"00001012050200 00001012050400","published":"00010101000000","role":"manual","syntax":"zmk","tags":"#api #manual #reference #zettelstore","title":"API: JSON structure of an access token"},"rights":62}, ...]
+# curl 'http://127.0.0.1:23123/z?q=title%3AAPI+ORDER+REVERSE+id+OFFSET+1&enc=json'
+{"query":"title:API ORDER REVERSE id OFFSET 1","human":"title HAS API ORDER REVERSE id OFFSET 1","list":[{"id":"00001012921200","meta":{"back":"00001012051200 00001012051400 00001012053300 00001012053400 00001012053800 00001012053900 00001012054000","backward":"00001012051200 00001012051400 00001012053300 00001012053400 00001012053800 00001012053900 00001012054000","box-number":"1","created":"00010101000000","forward":"00001003000000 00001006020400 00001010000000 00001010040100 00001010040200 00001010070200 00001010070300","modified":"20220201171959","published":"20220201171959","role":"manual","syntax":"zmk","tags":"#api #manual #reference #zettelstore","title":"API: Encoding of Zettel Access Rights"},"rights":62},{"id":"00001012921000","meta":{"back":"00001012050600 00001012051200","backward":"00001012050200 00001012050400 00001012050600 00001012051200","box-number":"1","created":"00010101000000","forward":"00001012050200 00001012050400","published":"00010101000000","role":"manual","syntax":"zmk","tags":"#api #manual #reference #zettelstore","title":"API: JSON structure of an access token"},"rights":62}, ...]
 ```
 
 The JSON object contains a key ''"list"'' where its value is a list of zettel JSON objects.
 These zettel JSON objects themselves contains the keys ''"id"'' (value is a string containing the [[zettel identifier|00001006050000]]), ''"meta"'' (value as a JSON object), and ''"rights"'' (encodes the [[access rights|00001012921200]] for the given zettel).
 The value of key ''"meta"'' effectively contains all metadata of the identified zettel, where metadata keys are encoded as JSON object keys and metadata values encoded as JSON strings.
@@ -64,11 +64,14 @@
 The result is a text file.
 The first word, separated by a horizontal tab (U+0009) contains the role name.
 The rest of the line consists of zettel identifier, where the corresponding zettel have this role.
 Zettel identifier are separated by a space character (U+0020).
 
-Of course, this list can be returned as a JSON object:
+Please note that the list is **not** sorted by the role name, so the same request might result in a different order.
+If you want a sorted list, you could sort it on the command line (``curl 'http://127.0.0.1:23123/z?q=|role' | sort``) or within the software that made the call to the Zettelstore.
+
+Of course, this list can also be returned as a JSON object:
 
 ```sh
 # curl 'http://127.0.0.1:23123/z?q=|role?enc=json'
 {"map":{"configuration":["00000000090002","00000000090000", ... ,"00000000000001"],"manual":["00001014000000", ... ,"00001000000000"],"zettel":["00010000000000", ... ,"00001012070500","00000000090001"]}}
 ```

Index: docs/manual/00001012053500.zettel
==================================================================
--- docs/manual/00001012053500.zettel
+++ docs/manual/00001012053500.zettel
@@ -6,14 +6,14 @@
 created: 20210726174524
 modified: 20230109105303
 
 The [[endpoint|00001012920000]] to work with evaluated metadata and content of a specific zettel is ''/z/{ID}'', where ''{ID}'' is a placeholder for the [[zettel identifier|00001006050000]].
 
-For example, to retrieve some evaluated data about this zettel you are currently viewing in [[Sexpr encoding|00001012920516]], just send a HTTP GET request to the endpoint ''/z/00001012053500''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header] with the query parameter ''enc=sexpr''.
+For example, to retrieve some evaluated data about this zettel you are currently viewing in [[Sz encoding|00001012920516]], just send a HTTP GET request to the endpoint ''/z/00001012053500''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header] with the query parameter ''enc=sz''.
 If successful, the output is a JSON object:
 ```sh
-# curl 'http://127.0.0.1:23123/z/00001012053500?enc=sexpr'
+# curl 'http://127.0.0.1:23123/z/00001012053500?enc=sz'
 ((PARA (TEXT "The") (SPACE) (LINK-ZETTEL () "00001012920000" (TEXT "endpoint")) (SPACE) (TEXT "to") (SPACE) (TEXT "work") (SPACE) (TEXT "with") (SPACE) (TEXT "evaluated") (SPACE) (TEXT "metadata") (SPACE) (TEXT "and") (SPACE) (TEXT "content") (SPACE) (TEXT "of") (SPACE) (TEXT "a") (SPACE) (TEXT "specific") (SPACE) (TEXT "zettel") (SPACE) (TEXT "is") (SPACE) (LITERAL-INPUT () "/z/{ID}") (TEXT ",") (SPACE) (TEXT "where") (SPACE) (LITERAL-INPUT () "{ID}") ...
 ```
 
 To select another encoding, you must provide the query parameter ''enc=ENCODING''.
 Others are ""[[html|00001012920510]]"", ""[[text|00001012920519]]"", and some [[more|00001012920500]].

Index: docs/manual/00001012053600.zettel
==================================================================
--- docs/manual/00001012053600.zettel
+++ docs/manual/00001012053600.zettel
@@ -12,11 +12,11 @@
 By using this endpoint, you are able to retrieve the structure of a zettel before it is evaluated.
 
 For example, to retrieve some data about this zettel you are currently viewing, just send a HTTP GET request to the endpoint ''/z/00001012053600''[^If [[authentication is enabled|00001010040100]], you must include the a valid [[access token|00001012050200]] in the ''Authorization'' header] with the query parameter ''parseonly'' (and other appropriate query parameter).
 For example:
 ```sh
-# curl 'http://127.0.0.1:23123/z/00001012053600?enc=sexpr&parseonly'
+# curl 'http://127.0.0.1:23123/z/00001012053600?enc=sz&parseonly'
 ((PARA (TEXT "The") (SPACE) (LINK-ZETTEL () "00001012920000" (TEXT "endpoint")) (SPACE) (TEXT "to") (SPACE) (TEXT "work") (SPACE) (TEXT "with") (SPACE) ...
 ```
 
 Similar to [[retrieving an encoded zettel|00001012053500]], you can specify an [[encoding|00001012920500]] and state which [[part|00001012920800]] of a zettel you are interested in.
 The same default values applies to this endpoint.

DELETED docs/manual/00001012053800.zettel
Index: docs/manual/00001012053800.zettel
==================================================================
--- docs/manual/00001012053800.zettel
+++ docs/manual/00001012053800.zettel
@@ -1,81 +0,0 @@
-id: 00001012053800
-title: API: Retrieve context of an existing zettel
-role: manual
-tags: #api #manual #zettelstore
-syntax: zmk
-created: 20210222151131
-modified: 20221208165112
-
-The context of an origin zettel consists of those zettel that are somehow connected to the origin zettel.
-Direct connections of an origin zettel to other zettel are visible via [[metadata values|00001006020000]], such as ''backward'', ''forward'' or other values with type [[identifier|00001006032000]] or [[set of identifier|00001006032500]].
-
-The context is defined by a __direction__, a __cost__, and a __limit__:
-* Direction: connections are directed.
-  For example, the metadata value of ''backward'' lists all zettel that link to the current zettel, while ''forward'' list all zettel to which the current zettel links to.
-  When you are only interested in one direction, set the parameter ''dir'' either to the value ""backward"" or ""forward"".
-  All other values, including a missing value, is interpreted as ""both"".
-* Cost: a normal direct connection has cost 5, an indirect connection is the length of the shortest path between two zettel.
-  The cost of a folgezettel or a precursor zettel is just 1, the cost of successor zettel and predecessor zettel are 2.
-  You should limit the cost by using the parameter ''cost''.
-  Its default value is ""17"".
-  A value of ""0"" does disable any cost check.
-* Limit: to set an upper bound for the returned context, you should use the parameter ''limit''.
-  Its default value is ""200"".
-  A value of ""0"" disables does not limit the number of elements returned.
-
-The search for the context of a zettel stops at the [[home zettel|00001004020000#home-zettel]].
-This zettel is connected to all other zettel.
-If it is included, the context would become too big and therefore unusable.
-
-To retrieve the context of an existing zettel, use the [[endpoint|00001012920000]] ''/x/{ID}''[^Mnemonic: conte**X**t].
-
-````
-# curl 'http://127.0.0.1:23123/x/00001012053800?limit=3&dir=forward&cost=5'
-{"id": "00001012053800","meta": {...},"rights":62,"list":[{"id": "00001012921000","meta": {...},"rights":62},{"id": "00001012920800","meta": {...},"rights":62},{"id": "00010000000000","meta": {...},"rights":62}]}
-````
-Formatted, this translates into:[^Metadata (key ''meta'') are hidden to make the overall structure easier to read.]
-````json
-{
-  "id": "00001012053800",
-  "meta": {...},
-  "rights": 62,
-  "list": [
-    {
-      "id": "00001012921000",
-      "meta": {...},
-      "rights":62
-    },
-    {
-      "id": "00001012920800",
-      "meta": {...},
-      "rights":62
-    },
-    {
-      "id": "00010000000000",
-      "meta": {...},
-      "rights":62
-    }
-  ]
-}
-````
-=== Keys
-The following top-level JSON keys are returned:
-; ''id''
-: The [[zettel identifier|00001006050000]] for which the context was requested.
-; ''meta'':
-: The metadata of the zettel, encoded as a JSON object.
-; ''rights''
-: An integer number that describes the [[access rights|00001012921200]] for the given zettel.
-; ''list''
-: A list of JSON objects with keys ''id'', ''meta'', and ''rights'' that contains the zettel of the context.
-
-=== HTTP Status codes
-; ''200''
-: Retrieval was successful, the body contains an appropriate JSON object.
-; ''400''
-: Request was not valid.
-; ''403''
-: You are not allowed to retrieve data of the given zettel.
-; ''404''
-: Zettel not found.
-  You probably used a zettel identifier that is not used in the Zettelstore.

Index: docs/manual/00001012920000.zettel
==================================================================
--- docs/manual/00001012920000.zettel
+++ docs/manual/00001012920000.zettel
@@ -2,11 +2,11 @@
 title: Endpoints used by the API
 role: manual
 tags: #api #manual #reference #zettelstore
 syntax: zmk
 created: 20210126175322
-modified: 20221219162335
+modified: 20230407125812
 
 All API endpoints conform to the pattern ''[PREFIX]LETTER[/ZETTEL-ID]'', where:
 ; ''PREFIX''
 : is the URL prefix (default: ""/""), configured via the ''url-prefix'' [[startup configuration|00001004010000]],
 ; ''LETTER''
@@ -19,11 +19,11 @@
 |= Letter:| Without zettel identifier | With [[zettel identifier|00001006050000]] | Mnemonic
 | ''a'' | POST: [[client authentication|00001012050200]] | | **A**uthenticate
 |       | PUT: [[renew access token|00001012050400]] |
 | ''o'' |  | GET: [[list zettel order|00001012054000]] | **O**rder
 | ''u'' |  | GET [[unlinked references|00001012053900]] | **U**nlinked
-| ''x'' | GET: [[retrieve administrative data|00001012070500]] | GET: [[list zettel context|00001012053800]] | Conte**x**t
+| ''x'' | GET: [[retrieve administrative data|00001012070500]] | | E**x**ecute
 |       | POST: [[execute command|00001012080100]]
 | ''z'' | GET: [[list zettel|00001012051200]] | GET: [[retrieve zettel|00001012053300]] | **Z**ettel
 |       | POST: [[create new zettel|00001012053200]] | PUT: [[update a zettel|00001012054200]]
 |       |  | DELETE: [[delete zettel|00001012054600]]
 |       |  | MOVE: [[rename zettel|00001012054400]]

Index: docs/manual/00001012920500.zettel
==================================================================
--- docs/manual/00001012920500.zettel
+++ docs/manual/00001012920500.zettel
@@ -1,16 +1,17 @@
 id: 00001012920500
-title: Encodings available via the [[API|00001012000000]]
+title: Encodings available via the API
 role: manual
 tags: #api #manual #reference #zettelstore
 syntax: zmk
 created: 20210126175322
-modified: 20230316180859
+modified: 20230403123653
 
 A zettel representation can be encoded in various formats for further processing.
+These will be retrieved via the [[API|00001012000000]].
 
 * [[html|00001012920510]]
 * [[md|00001012920513]]
-* [[sexpr|00001012920516]]
 * [[shtml|00001012920525]]
+* [[sz|00001012920516]]
 * [[text|00001012920519]]
 * [[zmk|00001012920522]]

Index: docs/manual/00001012920516.zettel
==================================================================
--- docs/manual/00001012920516.zettel
+++ docs/manual/00001012920516.zettel
@@ -1,45 +1,20 @@
 id: 00001012920516
-title: Sexpr Encoding
+title: Sz Encoding
 role: manual
 tags: #api #manual #reference #zettelstore
 syntax: zmk
 created: 20220422181104
-modified: 20230316182622
+modified: 20230403161458
 
-A zettel representation that is a [[s-expression|https://en.wikipedia.org/wiki/S-expression]] (also known as symbolic expression).
+A zettel representation that is a [[s-expression|00001012930000]] (also known as symbolic expression).
 
 It is (relatively) easy to parse and contain all relevant information of a zettel, metadata and content.
-For example, take a look at the Sexpr encoding of this page, which is available via the ""Info"" sub-page of this zettel: 
+For example, take a look at the Sz encoding of this page, which is available via the ""Info"" sub-page of this zettel: 
+
+* [[//z/00001012920516?enc=sz&part=zettel]],
+* [[//z/00001012920516?enc=sz&part=meta]],
+* [[//z/00001012920516?enc=sz&part=content]].
 
-* [[//z/00001012920516?enc=sexpr&part=zettel]],
-* [[//z/00001012920516?enc=sexpr&part=meta]],
-* [[//z/00001012920516?enc=sexpr&part=content]].
+Some zettel describe the [[Sz encoding|00001012931000]] in a more detailed way.
 
 If transferred via HTTP, the content type will be ''text/plain''.
-
-=== Syntax of s-expressions
-There are only two types of elements: atoms and lists.
-
-A list always starts with the left parenthesis (""''(''"", U+0028) and ends with a right parenthesis (""'')''"", U+0029).
-A list may contain a possibly empty sequence of elements, i.e. lists and / or atoms.
-Before the last element of a list of at least to elements, a full stop character (""''.''"", U+002E) signal a pair as the last two elements.
-This allows a more space economic storage of data.
-
-There are three syntactic forms for an atom: numbers, symbols and strings.
-
-A number is a non-empty sequence of digits (""0"" ... ""9"").
-The smallest number is ``0``, there are no negative numbers.
-
-A symbol is a non-empty sequence of printable characters, except left or right parenthesis.
-Unicode characters of the following categories contains printable characters in the above sense: letter (L), number (N), punctuation (P), symbol (S).
-Symbols are case-insensitive, i.e. ""''ZETTEL''"" and ""''zettel''"" denote the same symbol.
-
-A string starts with a quotation mark (""''"''"", U+0022), contains a possibly empty sequence of Unicode characters, and ends with a quotation mark.
-To allow a string to contain a quotations mark, it must be prefixed by one backslash (""''\\''"", U+005C).
-To allow a string to contain a backslash, it also must be prefixed by one backslash.
-Unicode characters with a code less than U+FF are encoded by by the sequence ""''\\xNM''"", where ''NM'' is the hex encoding of the character.
-Unicode characters with a code less than U+FFFF are encoded by by the sequence ""''\\uNMOP''"", where ''NMOP'' is the hex encoding of the character.
-Unicode characters with a code less than U+FFFFFF are encoded by by the sequence ""''\\UNMOPQR''"", where ''NMOPQR'' is the hex encoding of the character.
-In addition, the sequence ""''\\t''"" encodes a horizontal tab (U+0009), the sequence ""''\\n''"" encodes a line feed (U+000A).
-
-Atoms are separated by Unicode characters of category separator (Z).

Index: docs/manual/00001012920525.zettel
==================================================================
--- docs/manual/00001012920525.zettel
+++ docs/manual/00001012920525.zettel
@@ -2,13 +2,13 @@
 title: SHTML Encoding
 role: manual
 tags: #api #manual #reference #zettelstore
 syntax: zmk
 created: 20230316181044
-modified: 20230316182614
+modified: 20230403150657
 
-A zettel representation that is a [[s-expression|https://en.wikipedia.org/wiki/S-expression]], syntactically similar to the [[Sexpr encoding|00001012920516]], but denotes [[HTML|00001012920510]] semantics.
+A zettel representation that is a [[s-expression|00001012930000]], syntactically similar to the [[Sz encoding|00001012920516]], but denotes [[HTML|00001012920510]] semantics.
 It is derived from a XML encoding in s-expressions, called [[SXML|https://en.wikipedia.org/wiki/SXML]].
 
 It is (relatively) easy to parse and contains everything to transform it into real HTML.
 In contrast to HTML, SHTML is easier to parse and to manipulate.
 For example, take a look at the SHTML encoding of this page, which is available via the ""Info"" sub-page of this zettel: 
@@ -17,14 +17,14 @@
 * [[//z/00001012920525?enc=shtml&part=meta]],
 * [[//z/00001012920525?enc=shtml&part=content]].
 
 If transferred via HTTP, the content type will be ''text/plain''.
 
-Internally, if a zettel should be transformed into HTML, the zettel is translated into the [[Sexpr encoding|00001012920516]], which is transformed into this SHTML encoding to produce the [[HTML encoding|00001012920510]].
+Internally, if a zettel should be transformed into HTML, the zettel is translated into the [[Sz encoding|00001012920516]], which is transformed into this SHTML encoding to produce the [[HTML encoding|00001012920510]].
 
 === Syntax of SHTML
-There are only two types of elements: atoms and lists, similar to the Sexpr encoding.
+There are only two types of elements: atoms and lists, similar to the Sz encoding.
 
 A list always starts with the left parenthesis (""''(''"", U+0028) and ends with a right parenthesis (""'')''"", U+0029).
 A list may contain a possibly empty sequence of elements, i.e. lists and / or atoms.
 Before the last element of a list of at least to elements, a full stop character (""''.''"", U+002E) signal a pair as the last two elements.
 This allows a more space economic storage of data.

Index: docs/manual/00001012921000.zettel
==================================================================
--- docs/manual/00001012921000.zettel
+++ docs/manual/00001012921000.zettel
@@ -1,14 +1,15 @@
 id: 00001012921000
-title: API: JSON structure of an access token
+title: API: Structure of an access token
+role: manual
 tags: #api #manual #reference #zettelstore
 syntax: zmk
-role: manual
+created: 20210126175322
+modified: 20230412155303
 
 If the [[authentication process|00001012050200]] was successful, an access token with some additional data is returned.
 The same is true, if the access token was [[renewed|00001012050400]].
-The response is structured as an JSON object, with the following named values:
+The response is structured as a [[symbolic expression|00001012930000]] list, with the following elements:
 
-|=Name|Description
-|''access_token''|The access token itself, as string value, which is a [[JSON Web Token|https://tools.ietf.org/html/rfc7519]] (JWT, RFC 7915)
-|''token_type''|The type of the token, always set to ''"Bearer"'', as described in [[RFC 6750|https://tools.ietf.org/html/rfc6750]]
-|''expires_in''|An integer that gives a hint about the lifetime / endurance of the token, measured in seconds
+# The type of the token, always set to ''"Bearer"'', as described in [[RFC 6750|https://tools.ietf.org/html/rfc6750]]
+# The token itself, as string value, which is technically a [[JSON Web Token|https://tools.ietf.org/html/rfc7519]] (JWT, RFC 7915)
+# An integer that gives a hint about the lifetime / endurance of the token, measured in seconds

ADDED   docs/manual/00001012930000.zettel
Index: docs/manual/00001012930000.zettel
==================================================================
--- docs/manual/00001012930000.zettel
+++ docs/manual/00001012930000.zettel
@@ -0,0 +1,26 @@
+id: 00001012930000
+title: Symbolic Expression
+role: manual
+tags: #manual #reference #zettelstore
+syntax: zmk
+created: 20230403145644
+modified: 20230403154010
+
+A symbolic expression (also called __s-expression__) is a notation of a list-based tree.
+Inner nodes are lists of arbitrary length, outer nodes are primitive values (also called __atoms__) or the empty list.
+
+A symbolic expression is either
+* a primitive value (__atom__), or
+* a list of the form __(E,,1,, E,,2,, &hellip; E,,n,,)__, where __E,,i,,__ is itself a symbolic expression, separated by space characters.
+
+An atom is a number, a string, or a symbol.
+
+Symbolic expressions are used in programming languages like LISP or Scheme, where they denote both data structures and the program itself.
+This allows a LISP or Scheme program to process LISP or Scheme programs.
+That property is also used within Zettelstore.
+
+Symbolic expressions are relatively easy to read, to parse, and to process.
+
+=== See also
+* [[Syntax|00001012930500]] of symbolic expressions in the Zettelstore
+* [[S-expression @ Wikipedia|https://en.wikipedia.org/wiki/S-expression]]

ADDED   docs/manual/00001012930500.zettel
Index: docs/manual/00001012930500.zettel
==================================================================
--- docs/manual/00001012930500.zettel
+++ docs/manual/00001012930500.zettel
@@ -0,0 +1,77 @@
+id: 00001012930500
+title: Syntax of Symbolic Expressions
+role: manual
+tags: #manual #reference #zettelstore
+syntax: zmk
+created: 20230403151127
+modified: 20230403153609
+
+=== Syntax of lists
+A list always starts with the left parenthesis (""''(''"", U+0028) and ends with a right parenthesis (""'')''"", U+0029).
+A list may contain a possibly empty sequence of elements, i.e. lists and / or atoms.
+
+Internally, lists are composed of __cells__.
+A cell allows to store two values.
+The first value references the first element of a list.
+The second value references the rest of the list, or is the special value __nil__ if there is no rest of the list.
+
+However, it is possible to store an atom as the second value of the last cell.
+In this case, before the last element of a list of at least two elements, a full stop character (""''.''"", U+002E) signals such a cell as the last two elements.
+This allows a more space economic storage of data.
+
+A __proper__ list, which contains __nil__ as the second value of the last element might be pictured as follows:
+
+~~~draw
++---+---+   +---+---+         +---+---+
+| V | N +-->| V | N +-->   -->| V |   |
++-+-+---+   +-+-+---+         +-+-+---+
+  |           |                 |
+  v           v                 v
++-------+   +-------+    +-------+
+| Elem1 |   | Elem2 |    | ElemN |
++-------+   +-------+    +-------+
+~~~
+
+''V'' is a placeholder for a value, ''N'' is the reference to the next cell (also known as the rest / tail of the list).
+Above list will be represented as an symbolic expression as ''(Elem1 Elem2 ... ElemN)''
+
+An improper list will have a non-__nil__ reference to an atom as the very last element
+
+~~~draw
++---+---+   +---+---+         +---+---+
+| V | N +-->| V | N +-->   -->| V | V |
++-+-+---+   +-+-+---+         +-+-+-+-+
+  |           |                 |   |
+  v           v                 v   v
++-------+   +-------+    +-------+ +------+
+| Elem1 |   | Elem2 |    | ElemN | | Atom |
++-------+   +-------+    +-------+ +------+
+~~~
+
+Above improper list will be represented as an symbolic expression as ''(Elem1 Elem2 ... ElemN . Atom)''
+
+
+=== Syntax of numbers (atom)
+A number is a non-empty sequence of digits (""0"" ... ""9"").
+The smallest number is ``0``, there are no negative numbers.
+
+=== Syntax of symbols (atom)
+A symbol is a non-empty sequence of printable characters, except left or right parenthesis.
+Unicode characters of the following categories contains printable characters in the above sense: letter (L), number (N), punctuation (P), symbol (S).
+Symbols are case-sensitive, i.e. ""''ZETTEL''"" and ""''zettel''"" denote different symbols.
+
+=== Syntax of string (atom)
+
+A string starts with a quotation mark (""''"''"", U+0022), contains a possibly empty sequence of Unicode characters, and ends with a quotation mark.
+To allow a string to contain a quotations mark, it must be prefixed by one backslash (""''\\''"", U+005C).
+To allow a string to contain a backslash, it also must be prefixed by one backslash.
+Unicode characters with a code less than U+FF are encoded by by the sequence ""''\\xNM''"", where ''NM'' is the hex encoding of the character.
+Unicode characters with a code less than U+FFFF are encoded by by the sequence ""''\\uNMOP''"", where ''NMOP'' is the hex encoding of the character.
+Unicode characters with a code less than U+FFFFFF are encoded by by the sequence ""''\\UNMOPQR''"", where ''NMOPQR'' is the hex encoding of the character.
+In addition, the sequence ""''\\t''"" encodes a horizontal tab (U+0009), the sequence ""''\\n''"" encodes a line feed (U+000A).
+
+=== See also
+* Currently, Zettelstore uses [[Sxpf|https://codeberg.org/t73fde/sxpf]] (""Symbolic eXRression Framework"") to implement symbolic expression.
+  The project page might contain additional information about the full syntax.
+
+  Zettelstore only uses lists, numbers, string, and symbols to represent zettel.

ADDED   docs/manual/00001012931000.zettel
Index: docs/manual/00001012931000.zettel
==================================================================
--- docs/manual/00001012931000.zettel
+++ docs/manual/00001012931000.zettel
@@ -0,0 +1,81 @@
+id: 00001012931000
+title: Encoding of Sz
+role: manual
+tags: #api #manual #reference #zettelstore
+syntax: zmk
+created: 20230403153903
+modified: 20230405133249
+
+Zettel in a [[Sz encoding|00001012920516]] are represented as a [[symbolic expression|00001012930000]].
+To process these symbolic expressions, you need to know, how a specific part of a zettel is represented by a symbolic expression.
+
+Basically, each part of a zettel is represented as a list, often a nested list.
+The first element of that list is always an unique symbol, which denotes that part.
+The meaning / semantic of all other elements depend on that symbol.
+
+=== Zettel
+A full zettel is represented by a list of two elements.
+The first elements represents the metadata, the second element represents the zettel content.
+
+:::syntax
+__Zettel__ **=** ''('' [[__Metadata__|#metadata]] [[__Content__|#content]] '')''.
+:::
+
+=== Metadata
+
+Metadata is represented by a list, where the first element is the symbol ''META''.
+Following elements represent each metadatum[^""Metadatum"" is used as the singular form of metadata.] of a zettel in standard order.
+
+Standard order is: [[Title|00001006020000#title]], [[Role|00001006020000#role]], [[Tags|00001006020000#tags]], [[Syntax|00001006020000#syntax]], all other [[keys|00001006020000]] in alphabetic order.
+
+:::syntax
+__Metadata__ **=** ''(META'' [[__Metadatum__|00001012931200]] __Metadatum__ &hellip; __Metadatum__ '')''.
+:::
+=== Content
+
+Zettel content is represented by a block.
+:::syntax
+__Content__ **=** [[__Block__|#block]].
+:::
+
+==== Block
+A block is represented by a list with the symbol ''BLOCK'' as the first element.
+All following elements represent a nested [[block-structured element|00001007030000]].
+
+:::syntax
+[!block|__Block__] **=** ''(BLOCK'' [[__BlockElement__|00001012931400]] __BlockElement__ &hellip; __BlockElement__ '')''.
+:::
+
+==== Inline
+Both block-structured elements and some metadata values may contain [[inline-structured elements|00001007040000]].
+Similar, inline-structured elements are represented as follows:
+
+:::syntax
+__Inline__ **=** ''(INLINE'' [[__InlineElement__|00001012931600]] __InlineElement__ &hellip; __InlineElement__ '')''.
+:::
+
+==== Attribute
+[[Attributes|00001007050000]] may be specified for both block- and inline- structured elements.
+Attributes are represented by the following schema.
+Please note, the the symbol ''quote'' is lower-case by intention.
+
+:::syntax
+__Attribute__ **=** ''('' **[** ''quote'' ''('' [[__AttributeKeyValue__|00001012931800]] __AttributeKeyValue__ &hellip; __AttributeKeyValue__ '')'' **]** ')'.
+:::
+
+Either, there are no attributes.
+These are specified by the empty list ''()''.
+Or there are attributes.
+In this case, the first element of the list must be the symbol ''quote'': ''(quote'' ''('' A,,1,, A,,2,, &hellip; A,,n,, '')'''')''.
+
+=== Other
+A list with ''UNKNOWN'' as its first element signals an internal error during transforming a zettel into the Sz encoding.
+It may be ignored, or it may produce an error.
+
+:::syntax
+__Unknown__ **=** ''(UNKNOWN'' Object &hellip; '')''.
+:::
+
+The list may only contain the symbol ''UNKNOWN'', or additionally an unlimited amount of other objects.
+
+Similar, any symbol with the pattern ''**xyz:NOT-FOUND**'', where ''xyz'' is any string, signals an internal error.

ADDED   docs/manual/00001012931200.zettel
Index: docs/manual/00001012931200.zettel
==================================================================
--- docs/manual/00001012931200.zettel
+++ docs/manual/00001012931200.zettel
@@ -0,0 +1,41 @@
+id: 00001012931200
+title: Encoding of Sz Metadata
+role: manual
+tags: #api #manual #reference #zettelstore
+syntax: zmk
+created: 20230403161618
+modified: 20230405121932
+
+A single metadata (""metadatum"") is represented by a triple: a symbol representing the type, a symbol representing the key, and either a string or a list that represent the value.
+
+The key symbol must be ""quoted"", i.e. for the key ""title"": ''(quote title)''.
+This property may be relaxed in future versions of the Zettelstore.
+
+The symbol depends on the [[metadata key type|00001006030000]].
+The value also depends somehow on the key type: a set of values is represented as a list, all other values are represented by a string, even if it is a number.
+
+The following table maps key types to symbols and to the type of the value representation.
+
+|=Key Type<| Symbol<| Value<
+| [[Credential|00001006031000]] | ''CREDENTIAL'' | string
+| [[EString|00001006031500]] | ''EMPTY-STRING'' | string
+| [[Identifier|00001006032000]] | ''ZID'' | string
+| [[IdentifierSet|00001006032500]] | ''ZID-SET'' | list
+| [[Number|00001006033000]] | ''NUMBER'' | string
+| [[String|00001006033500]] | ''STRING'' | string
+| [[TagSet|00001006034000]] | ''TAG-SET'' | list
+| [[Timestamp|00001006034500]] | ''TIMESTAMP'' | string
+| [[URL|00001006035000]] | ''URL'' | string
+| [[Word|00001006035500]] | ''WORD'' | string
+| [[WordSet|00001006036000]] | ''WORD-SET'' | list
+| [[Zettelmarkup|00001006036500]] | ''ZETTELMARKUP'' | string
+
+If the value is represented as a list, its first element is the symbol ''list'', and all other elements are strings with the appropriate values.
+
+:::syntax
+__ListValue__ **=** ''(list'' String,,1,, String,,2,, &hellip; String,,n,, '')''.
+:::
+
+Examples:
+* The title of this zettel is represented as: ''(EMPTY-STRING (quote title) "Encoding of Sz Metadata")''
+* The tags of this zettel are represented as: ''(TAG-SET (quote tags) (list "#api" "#manual" "#reference" "#zettelstore"))''

ADDED   docs/manual/00001012931400.zettel
Index: docs/manual/00001012931400.zettel
==================================================================
--- docs/manual/00001012931400.zettel
+++ docs/manual/00001012931400.zettel
@@ -0,0 +1,186 @@
+id: 00001012931400
+title: Encoding of Sz Block Elements
+role: manual
+tags: #api #manual #reference #zettelstore
+syntax: zmk
+created: 20230403161803
+modified: 20230405132916
+
+=== ''PARA''
+:::syntax
+__Paragraph__ **=** ''(PARA'' [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+A paragraph is just a list of inline elements.
+
+=== ''HEADING''
+:::syntax
+__Heading__ **=** ''(HEADING'' Number [[__Attributes__|00001012931000#attribute]] String,,1,, String,,2,, [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+A heading consists of a number, which specifies its level (1 -- 5), its optional attributes.
+The first string is a ""slug"" of the heading text, i.e. transformed it to lower case, replaced space character with minus sign, and some more.
+The second string is the slug, but made unique for the whole zettel.
+Then the heading text follows as a sequence of inline elements.
+
+=== ''THEMATIC''
+:::syntax
+__Thematic__ **=** ''(THEMATIC'' [[__Attributes__|00001012931000#attribute]] '')''.
+:::
+
+=== ''ORDERED'', ''UNORDERED'', ''QUOTATION''
+These three symbols are specifying different kinds of lists / enumerations: an ordered list, an unordered list, and a quotation list.
+Their structure is the same.
+
+:::syntax
+__OrderedList__ **=** ''(ORDERED'' __ListElement__ &hellip; '')''.
+
+__UnorderedList__ **=** ''(UNORDERED'' __ListElement__ &hellip; '')''.
+
+__QuotationList__ **=** ''(QUOTATION'' __ListElement__ &hellip; '')''.
+:::
+
+:::syntax
+__ListElement__ **=** [[__Block__|00001012931000#block]] **|** [[__Inline__|00001012931000#inline]].
+:::
+A list element is either a block or an inline.
+If it is a block, it may contain a nested list.
+=== ''DESCRIPTION''
+:::syntax
+__Description__ **=** ''(DESCRIPTION'' __DescriptionTerm__ __DescriptionValues__ __DescriptionTerm__ __DescriptionValues__ &hellip; '')''.
+:::
+A description is a sequence of one ore more terms and values.
+
+:::syntax
+__DescriptionTerm__ **=** [[__Inline__|00001012931000#inline]].
+:::
+A description term is just an inline-structured value.
+
+:::syntax
+__DescriptionValues__ **=** ''(BLOCK'' [[__Block__|00001012931000#block]] &hellip; '')''.
+:::
+Description values are sequences of blocks.
+
+=== ''TABLE''
+:::syntax
+__Table__ **=** ''(TABLE'' __TableHeader__ __TableRow__ &hellip; '')''.
+:::
+A table is a table header and a sequence of table rows.
+
+:::syntax
+__TableHeader__ **=** ''()'' **|** ''(list'' __TableCell__ &hellip; '')''.
+:::
+A table header is either the empty list or a list of table cells stating with the ''list'' symbol.
+
+:::syntax
+__TableRow__ **=** ''(list'' __TableCell__ &hellip; '')''.
+:::
+A table row is a list with the initial symbol ''list'', followed by table cells.
+
+=== ''CELL'', ''CELL-*''
+There are four kinds of table cells, one for each possible cell alignment.
+The structure is the same for all kind.
+
+:::syntax
+__TableCell__ **=** __DefaultCell__ **|** __CenterCell__ **|** __LeftCell__ **|** __RightCell__.
+:::
+
+:::syntax
+__DefaultCell__ **=** ''(CELL'' [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The cell content, specified by the sequence of inline elements, used the default alignment.
+
+:::syntax
+__CenterCell__ **=** ''(CELL-CENTER'' [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The cell content, specified by the sequence of inline elements, is centered aligned.
+
+:::syntax
+__LeftCell__ **=** ''(CELL-LEFT'' [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The cell content, specified by the sequence of inline elements, is left aligned.
+
+:::syntax
+__RightCell__ **=** ''(CELL-RIGHT'' [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The cell content, specified by the sequence of inline elements, is right aligned.
+
+=== ''REGION-*''
+The following lists specifies different kinds of regions.
+A region treat a sequence of block elements to be belonging together in certain ways.
+The have a similar structure.
+
+:::syntax
+__BlockRegion__ **=** ''(REGION-BLOCK'' [[__Attributes__|00001012931000#attribute]] [[__Block__|00001012931000#block]] [[__Inline__|00001012931000#inline]] '')''.
+:::
+A block region just treats the block to belong in an unspecified way.
+Typically, the reason is given in the attributes.
+The inline describes the block.
+
+:::syntax
+__QuoteRegion__ **=** ''(REGION-QUOTE'' [[__Attributes__|00001012931000#attribute]] [[__Block__|00001012931000#block]] [[__Inline__|00001012931000#inline]] '')''.
+:::
+A block region just treats the block to contain a longer quotation.
+Attributes may further specify the quotation.
+The inline typically describes author / source of the quotation.
+
+:::syntax
+__VerseRegion__ **=** ''(REGION-VERSE'' [[__Attributes__|00001012931000#attribute]] [[__Block__|00001012931000#block]] [[__Inline__|00001012931000#inline]] '')''.
+:::
+A block region just treats the block to contain a verse.
+Soft line break are transformed into hard line breaks to save the structure of the verse / poem.
+Attributes may further specify something.
+The inline typically describes author / source of the verse.
+
+=== ''VERBATIM-*''
+The following lists specifies some literal text of more than one line.
+The structure is always the same, the initial symbol denotes the actual usage.
+The content is encoded as a string, most likely to contain control characters that signals the end of a line.
+
+:::syntax
+__CommentVerbatim__ **=** ''(VERBATIM-COMMENT'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be treated as an internal comment not to be interpreted further.
+
+:::syntax
+__EvalVerbatim__ **=** ''(VERBATIM-EVAL'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be evaluated by an (external) software to produce some derived content.
+
+:::syntax
+__HTMLVerbatim__ **=** ''(VERBATIM-HTML'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains HTML code.
+
+:::syntax
+__MathVerbatim__ **=** ''(VERBATIM-MATH'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be treated as special code to be interpreted as mathematical formulas.
+
+:::syntax
+__CodeVerbatim__ **=** ''(VERBATIM-CODE'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be treated as (executable) code.
+
+:::syntax
+__ZettelVerbatim__ **=** ''(VERBATIM-ZETTEL'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be treated as (nested) zettel content.
+
+=== ''BLOB''
+:::syntax
+__BLOB__ **=** ''(BLOB'' [[__Inline__|00001012931000#inline]] String,,1,, String,,2,, '')''.
+:::
+A BLOB contains an image in block mode.
+The inline states some description.
+The first string contains the syntax of the image.
+The second string contains the actual image.
+If the syntax is ""SVG"", then the second string contains the SVG code.
+Otherwise the (binary) image data is encoded with base64.
+
+=== ''TRANSCLUDE''
+:::syntax
+__Transclude__ **=** ''(TRANSCLUDE'' [[__Attributes__|00001012931000#attribute]] [[__Reference__|00001012931900]] '')''.
+:::
+A transclude list only occurs for a parsed zettel, but not for a evaluated zettel.
+Evaluating a zettel also means that all transclusions are resolved.
+
+__Reference__ denotes the zettel to be transcluded.

ADDED   docs/manual/00001012931600.zettel
Index: docs/manual/00001012931600.zettel
==================================================================
--- docs/manual/00001012931600.zettel
+++ docs/manual/00001012931600.zettel
@@ -0,0 +1,212 @@
+id: 00001012931600
+title: Encoding of Sz Inline Elements
+role: manual
+tags: #api #manual #reference #zettelstore
+syntax: zmk
+created: 20230403161845
+modified: 20230405123222
+
+=== ''TEXT''
+:::syntax
+__Text__ **=** ''(TEXT'' String '')''.
+:::
+Specifies the string as some text content, typically a word.
+
+=== ''SPACE''
+:::syntax
+__Space__ **=** ''(SPACE'' **[** String **]** '')''.
+:::
+Specifies some space, typically white space.
+If the string is not given it is assumed to be ''" "'' (one space character).
+Otherwise it contains the space characters.
+
+=== ''SOFT''
+:::syntax
+__Soft__ **=** ''(SOFT)''.
+:::
+Denotes a soft line break.
+It is typically translated into a space character, but signals the point in the textual content, where a line break occurred.
+
+=== ''HARD''
+:::syntax
+__Hard__ **=** ''(HARD)''.
+:::
+Specifies a hard line break, i.e. the user wants to have a line break here.
+
+=== ''LINK-*''
+The following lists specify various links, based on the full reference.
+They all have the same structure, with a trailing sequence of __InlineElements__ that contain the linked text.
+
+:::syntax
+__InvalidLink__ **=** ''(LINK-INVALID'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The string contains the invalid link specification.
+
+:::syntax
+__ZettelLink__ **=** ''(LINK-ZETTEL'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The string contains the zettel identifier, a zettel reference.
+
+:::syntax
+__SelfLink__ **=** ''(LINK-SELF'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The string contains the number sign character and the name of a zettel mark.
+It reference the same zettel where it occurs.
+
+:::syntax
+__FoundLink__ **=** ''(LINK-FOUND'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The string contains a zettel identifier, a zettel reference, of a zettel known to be included in the Zettelstore.
+
+:::syntax
+__BrokenLink__ **=** ''(LINK-BROKEN'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The string contains a zettel identifier, a zettel reference, of a zettel known to be __not__ included in the Zettelstore.
+
+:::syntax
+__HostedLink__ **=** ''(LINK-HOSTED'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The string contains a link starting with one slash character, denoting an absolute local reference.
+
+:::syntax
+__BasedLink__ **=** ''(LINK-BASED'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The string contains a link starting with two slash characters, denoting a local reference interpreted relative to the Zettelstore base URL.
+
+:::syntax
+__QueryLink__ **=** ''(LINK-BASED'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The string contains a [[query expression|00001007700000]].
+
+:::syntax
+__ExternalLink__ **=** ''(LINK-EXTERNAL'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The string contains a full URL, referencing a resource outside of the Zettelstore server.
+
+=== ''EMBED''
+:::syntax
+__Embed__ **=** ''(EMBED'' [[__Attributes__|00001012931000#attribute]] [[__Reference__|00001012931900]] String [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+Specifies an embedded element, in most cases some image content or an inline transclusion.
+A transclusion will only be used, if the zettel content was not evaluated.
+
+__Reference__ denoted the referenced zettel.
+
+If the string value is empty, it is an inline transclusion.
+Otherwise it contains the syntax of an image.
+
+The __InlineElement__ at the end of the list is interpreted as describing text.
+
+=== ''EMBED-BLOB''
+:::syntax
+__EmbedBLOB__ **=** ''(EMBED-BLOB'' [[__Attributes__|00001012931000#attribute]] String,,1,, String,,2,, '')''.
+:::
+If used if some processed image has to be embedded inside some inline material.
+The first string specifies the syntax of the image content.
+The second string contains the image content.
+If the syntax is ""SVG"", the image content is not further encoded.
+Otherwise a base64 encoding is used.
+
+=== ''CITE''
+:::syntax
+__CiteBLOB__ **=** ''(CITE'' [[__Attributes__|00001012931000#attribute]] String [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The string contains the citation key.
+
+=== ''MARK''
+:::syntax
+__Mark__ **=** ''(MARK'' String,,1,, String,,2,, String,,3,, [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The first string is the mark string used in the content.
+The second string is the mark string transformed to a slug, i.e. transformed to lower case, remove non-ASCII characters.
+The third string is the slug string, but made unique for the whole zettel.
+Then follows the marked text as a sequence of __InlineElement__s.
+
+=== ''ENDNOTE''
+:::syntax
+__Endnote__ **=** ''(ENDNOTE'' [[__Attributes__|00001012931000#attribute]] ''(quote'' [[__InlineElement__|00001012931600]] &hellip; '')'''')''.
+:::
+Specifies endnote / footnote text.
+
+=== ''FORMAT-*''
+The following lists specifies some inline text formatting.
+The structure is always the same, the initial symbol denotes the actual formatting.
+
+:::syntax
+__DeleteFormat__ **=** ''(FORMAT-DELETE'' [[__Attributes__|00001012931000#attribute]] [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The inline text should be treated as deleted.
+
+:::syntax
+__EmphasizeFormat__ **=** ''(FORMAT-EMPH'' [[__Attributes__|00001012931000#attribute]] [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The inline text should be treated as emphasized.
+
+:::syntax
+__InsertFormat__ **=** ''(FORMAT-INSERT'' [[__Attributes__|00001012931000#attribute]] [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The inline text should be treated as inserted.
+
+:::syntax
+__QuoteFormat__ **=** ''(FORMAT-QUOTE'' [[__Attributes__|00001012931000#attribute]] [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The inline text should be treated as quoted text.
+
+:::syntax
+__SpanFormat__ **=** ''(FORMAT-SPAN'' [[__Attributes__|00001012931000#attribute]] [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The inline text should be treated as belonging together in a certain, yet unspecified way.
+
+:::syntax
+__SubScriptFormat__ **=** ''(FORMAT-SUB'' [[__Attributes__|00001012931000#attribute]] [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The inline text should be treated as sub-scripted text.
+
+:::syntax
+__SuperScriptFormat__ **=** ''(FORMAT-SUPER'' [[__Attributes__|00001012931000#attribute]] [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The inline text should be treated as super-scripted text.
+
+:::syntax
+__StrongFormat__ **=** ''(FORMAT-STRONG'' [[__Attributes__|00001012931000#attribute]] [[__InlineElement__|00001012931600]] &hellip; '')''.
+:::
+The inline text should be treated as strongly emphasized.
+
+=== ''LITERAL-*''
+The following lists specifies some literal text.
+The structure is always the same, the initial symbol denotes the actual usage.
+
+:::syntax
+__CodeLiteral__ **=** ''(LITERAL-CODE'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be treated as executable code.
+
+:::syntax
+__CommentLiteral__ **=** ''(LITERAL-COMMENT'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be treated as an internal comment not to be interpreted further.
+
+:::syntax
+__HTMLLiteral__ **=** ''(LITERAL-HTML'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be treated as HTML code.
+
+:::syntax
+__InputLiteral__ **=** ''(LITERAL-INPUT'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be treated as input entered by an user.
+
+:::syntax
+__MathLiteral__ **=** ''(LITERAL-MATH'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be treated as special code to be interpreted as mathematical formulas.
+
+:::syntax
+__OutputLiteral__ **=** ''(LITERAL-OUTPUT'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be treated as computer output to be read by an user.
+
+:::syntax
+__ZettelLiteral__ **=** ''(LITERAL-ZETTEL'' [[__Attributes__|00001012931000#attribute]] String '')''.
+:::
+The string contains text that should be treated as (nested) zettel content.

ADDED   docs/manual/00001012931800.zettel
Index: docs/manual/00001012931800.zettel
==================================================================
--- docs/manual/00001012931800.zettel
+++ docs/manual/00001012931800.zettel
@@ -0,0 +1,28 @@
+id: 00001012931800
+title: Encoding of Sz Attribute Values
+role: manual
+tags: #api #manual #reference #zettelstore
+syntax: zmk
+created: 20230403161923
+modified: 20230403163701
+
+An attribute is represented by a single cell.
+The first element of the cell references the attribute key, the second value the corresponding value.
+
+:::syntax
+__AttributeKeyValue__ **=** ''('' __AttributeKey__ ''.'' __AttributeValue__ '')''.
+:::
+
+__AttributeKey__ and __AttributeValue__ are [[string values|00001012930500]].
+
+An empty key denotes the generic attribute.
+
+A key with the value ''"-"'' specifies the default attribute.
+In this case, the attribute value is not interpreted.
+
+Some examples:
+* ''()'' represents the absence of attributes,
+* ''(quote (("-" . "")))'' represent the default attribute,
+* ''(quote (("-" . "") ("" . "syntax")))'' adds the generic attrribute with the value ""syntax"",
+* ''(quote ())'' will also represent the absence of attribute (in a more complicated way),
+* ''(quote (("lang" . "en")))'' denote the attribute key ""lang"" with a value ""en"".

ADDED   docs/manual/00001012931900.zettel
Index: docs/manual/00001012931900.zettel
==================================================================
--- docs/manual/00001012931900.zettel
+++ docs/manual/00001012931900.zettel
@@ -0,0 +1,38 @@
+id: 00001012931900
+title: Encoding of Sz Reference Values
+role: manual
+tags: #api #manual #reference #zettelstore
+syntax: zmk
+created: 20230405123046
+modified: 20230405124516
+
+A reference is encoded as the actual reference value, and a symbol describing the state of that actual reference value.
+
+:::syntax
+__Reference__ **=** ''(quote'' __ReferenceState__ String '')''.
+:::
+The ''quote'' is needed for internal reasons, the string contains the actual reference value.
+
+:::syntax
+__ReferenceState__ **=** ''INVALID'' **|** ''ZETTEL'' **|** ''SELF'' **|** ''FOUND'' **|** ''BROKEN'' **|** ''HOSTED'' **|** ''BASED'' **|** ''QUERY'' **|** ''EXTERNAL''.
+:::
+
+The meaning of the state symbols corresponds to that of the symbols used for the description of [[link references|00001012931600#link]].
+
+; ''INVALID''
+: The reference value is invalid.
+; ''ZETTEL''
+: The reference value is a reference to a zettel.
+  This value is only possible before evaluating the zettel.
+; ''SELF''
+: The reference value is a reference to the same zettel, to a specific mark.
+; ''FOUND''
+: The reference value is a valid reference to an existing zettel.
+  This value is only possible after evaluating the zettel.
+; ''BROKEN''
+: The reference value is a valid reference to an missing zettel.
+  This value is only possible after evaluating the zettel.
+; ''HOSTED''
+; ''BASED''
+; ''QUERY''
+; ''EXTERNAL''

DELETED domain/content.go
Index: domain/content.go
==================================================================
--- domain/content.go
+++ domain/content.go
@@ -1,129 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package domain
-
-import (
-	"bytes"
-	"encoding/base64"
-	"errors"
-	"io"
-	"unicode"
-	"unicode/utf8"
-
-	"zettelstore.de/z/input"
-)
-
-// Content is just the content of a zettel.
-type Content struct {
-	data     []byte
-	isBinary bool
-}
-
-// NewContent creates a new content from a string.
-func NewContent(data []byte) Content {
-	return Content{data: data, isBinary: IsBinary(data)}
-}
-
-// Length returns the number of bytes stored.
-func (zc *Content) Length() int { return len(zc.data) }
-
-// Equal compares two content values.
-func (zc *Content) Equal(o *Content) bool {
-	if zc == nil {
-		return o == nil
-	}
-	if zc.isBinary != o.isBinary {
-		return false
-	}
-	return bytes.Equal(zc.data, o.data)
-}
-
-// Set content to new string value.
-func (zc *Content) Set(data []byte) {
-	zc.data = data
-	zc.isBinary = IsBinary(data)
-}
-
-// Write it to a Writer
-func (zc *Content) Write(w io.Writer) (int, error) {
-	return w.Write(zc.data)
-}
-
-// AsString returns the content itself is a string.
-func (zc *Content) AsString() string { return string(zc.data) }
-
-// AsBytes returns the content itself is a byte slice.
-func (zc *Content) AsBytes() []byte { return zc.data }
-
-// IsBinary returns true if the content contains non-unicode values or is,
-// interpreted a text, with a high probability binary content.
-func (zc *Content) IsBinary() bool { return zc.isBinary }
-
-// TrimSpace remove some space character in content, if it is not binary content.
-func (zc *Content) TrimSpace() {
-	if zc.isBinary {
-		return
-	}
-	inp := input.NewInput(zc.data)
-	pos := inp.Pos
-	for inp.Ch != input.EOS {
-		if input.IsEOLEOS(inp.Ch) {
-			inp.Next()
-			pos = inp.Pos
-			continue
-		}
-		if !input.IsSpace(inp.Ch) {
-			break
-		}
-		inp.Next()
-	}
-	zc.data = bytes.TrimRightFunc(inp.Src[pos:], unicode.IsSpace)
-}
-
-// Encode content for future transmission.
-func (zc *Content) Encode() (data, encoding string) {
-	if !zc.isBinary {
-		return zc.AsString(), ""
-	}
-	return base64.StdEncoding.EncodeToString(zc.data), "base64"
-}
-
-// SetDecoded content to the decoded value of the given string.
-func (zc *Content) SetDecoded(data, encoding string) error {
-	switch encoding {
-	case "":
-		zc.data = []byte(data)
-	case "base64":
-		decoded, err := base64.StdEncoding.DecodeString(data)
-		if err != nil {
-			return err
-		}
-		zc.data = decoded
-	default:
-		return errors.New("unknown encoding " + encoding)
-	}
-	zc.isBinary = IsBinary(zc.data)
-	return nil
-}
-
-// IsBinary returns true if the given data appears to be non-text data.
-func IsBinary(data []byte) bool {
-	if !utf8.Valid(data) {
-		return true
-	}
-	l := len(data)
-	for i := 0; i < l; i++ {
-		if data[i] == 0 {
-			return true
-		}
-	}
-	return false
-}

DELETED domain/content_test.go
Index: domain/content_test.go
==================================================================
--- domain/content_test.go
+++ domain/content_test.go
@@ -1,66 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package domain_test
-
-import (
-	"testing"
-
-	"zettelstore.de/z/domain"
-)
-
-func TestContentIsBinary(t *testing.T) {
-	t.Parallel()
-	td := []struct {
-		s   string
-		exp bool
-	}{
-		{"abc", false},
-		{"äöü", false},
-		{"", false},
-		{string([]byte{0}), true},
-	}
-	for i, tc := range td {
-		content := domain.NewContent([]byte(tc.s))
-		got := content.IsBinary()
-		if got != tc.exp {
-			t.Errorf("TC=%d: expected %v, got %v", i, tc.exp, got)
-		}
-	}
-}
-
-func TestTrimSpace(t *testing.T) {
-	t.Parallel()
-	testcases := []struct {
-		in, exp string
-	}{
-		{"", ""},
-		{" ", ""},
-		{"abc", "abc"},
-		{" abc", " abc"},
-		{"abc ", "abc"},
-		{"abc \n", "abc"},
-		{"abc\n ", "abc"},
-		{"\nabc", "abc"},
-		{" \nabc", "abc"},
-		{" \n abc", " abc"},
-		{" \n\n abc", " abc"},
-		{" \n \n abc", " abc"},
-		{" \n \n abc \n \n ", " abc"},
-	}
-	for _, tc := range testcases {
-		c := domain.NewContent([]byte(tc.in))
-		c.TrimSpace()
-		got := c.AsString()
-		if got != tc.exp {
-			t.Errorf("TrimSpace(%q) should be %q, but got %q", tc.in, tc.exp, got)
-		}
-	}
-}

DELETED domain/id/id.go
Index: domain/id/id.go
==================================================================
--- domain/id/id.go
+++ domain/id/id.go
@@ -1,163 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-// Package id provides domain specific types, constants, and functions about
-// zettel identifier.
-package id
-
-import (
-	"strconv"
-	"time"
-
-	"zettelstore.de/c/api"
-)
-
-// Zid is the internal identifier of a zettel. Typically, it is a
-// time stamp of the form "YYYYMMDDHHmmSS" converted to an unsigned integer.
-// A zettelstore implementation should try to set the last two digits to zero,
-// e.g. the seconds should be zero,
-type Zid uint64
-
-// Some important ZettelIDs.
-const (
-	Invalid = Zid(0) // Invalid is a Zid that will never be valid
-)
-
-// ZettelIDs that are used as Zid more than once.
-//
-// Note: if you change some values, ensure that you also change them in the
-// Constant box. They are mentioned there literally, because these
-// constants are not available there.
-var (
-	ConfigurationZid   = MustParse(api.ZidConfiguration)
-	BaseTemplateZid    = MustParse(api.ZidBaseTemplate)
-	LoginTemplateZid   = MustParse(api.ZidLoginTemplate)
-	ListTemplateZid    = MustParse(api.ZidListTemplate)
-	ZettelTemplateZid  = MustParse(api.ZidZettelTemplate)
-	InfoTemplateZid    = MustParse(api.ZidInfoTemplate)
-	FormTemplateZid    = MustParse(api.ZidFormTemplate)
-	RenameTemplateZid  = MustParse(api.ZidRenameTemplate)
-	DeleteTemplateZid  = MustParse(api.ZidDeleteTemplate)
-	ContextTemplateZid = MustParse(api.ZidContextTemplate)
-	ErrorTemplateZid   = MustParse(api.ZidErrorTemplate)
-	RoleCSSMapZid      = MustParse(api.ZidRoleCSSMap)
-	EmojiZid           = MustParse(api.ZidEmoji)
-	TOCNewTemplateZid  = MustParse(api.ZidTOCNewTemplate)
-	DefaultHomeZid     = MustParse(api.ZidDefaultHome)
-)
-
-const maxZid = 99999999999999
-
-// ParseUint interprets a string as a possible zettel identifier
-// and returns its integer value.
-func ParseUint(s string) (uint64, error) {
-	res, err := strconv.ParseUint(s, 10, 47)
-	if err != nil {
-		return 0, err
-	}
-	if res == 0 || res > maxZid {
-		return res, strconv.ErrRange
-	}
-	return res, nil
-}
-
-// Parse interprets a string as a zettel identification and
-// returns its value.
-func Parse(s string) (Zid, error) {
-	if len(s) != 14 {
-		return Invalid, strconv.ErrSyntax
-	}
-	res, err := ParseUint(s)
-	if err != nil {
-		return Invalid, err
-	}
-	return Zid(res), nil
-}
-
-// MustParse tries to interpret a string as a zettel identifier and returns
-// its value or panics otherwise.
-func MustParse(s api.ZettelID) Zid {
-	zid, err := Parse(string(s))
-	if err == nil {
-		return zid
-	}
-	panic(err)
-}
-
-// String converts the zettel identification to a string of 14 digits.
-// Only defined for valid ids.
-func (zid Zid) String() string {
-	var result [14]byte
-	zid.toByteArray(&result)
-	return string(result[:])
-}
-
-// Bytes converts the zettel identification to a byte slice of 14 digits.
-// Only defined for valid ids.
-func (zid Zid) Bytes() []byte {
-	var result [14]byte
-	zid.toByteArray(&result)
-	return result[:]
-}
-
-// toByteArray converts the Zid into a fixed byte array, usable for printing.
-//
-// Based on idea by Daniel Lemire: "Converting integers to fix-digit representations quickly"
-// https://lemire.me/blog/2021/11/18/converting-integers-to-fix-digit-representations-quickly/
-func (zid Zid) toByteArray(result *[14]byte) {
-	date := uint64(zid) / 1000000
-	fullyear := date / 10000
-	century := fullyear / 100
-	year := fullyear % 100
-	monthday := date % 10000
-	month := monthday / 100
-	day := monthday % 100
-	time := uint64(zid) % 1000000
-	hmtime := time / 100
-	second := time % 100
-	hour := hmtime / 100
-	minute := hmtime % 100
-	result[0] = byte(century/10) + '0'
-	result[1] = byte(century%10) + '0'
-	result[2] = byte(year/10) + '0'
-	result[3] = byte(year%10) + '0'
-	result[4] = byte(month/10) + '0'
-	result[5] = byte(month%10) + '0'
-	result[6] = byte(day/10) + '0'
-	result[7] = byte(day%10) + '0'
-	result[8] = byte(hour/10) + '0'
-	result[9] = byte(hour%10) + '0'
-	result[10] = byte(minute/10) + '0'
-	result[11] = byte(minute%10) + '0'
-	result[12] = byte(second/10) + '0'
-	result[13] = byte(second%10) + '0'
-}
-
-// IsValid determines if zettel id is a valid one, e.g. consists of max. 14 digits.
-func (zid Zid) IsValid() bool { return 0 < zid && zid <= maxZid }
-
-// ZidLayout to transform a date into a Zid and into other internal dates.
-const ZidLayout = "20060102150405"
-
-// New returns a new zettel id based on the current time.
-func New(withSeconds bool) Zid {
-	now := time.Now().Local()
-	var s string
-	if withSeconds {
-		s = now.Format(ZidLayout)
-	} else {
-		s = now.Format("20060102150400")
-	}
-	res, err := Parse(s)
-	if err != nil {
-		panic(err)
-	}
-	return res
-}

DELETED domain/id/id_test.go
Index: domain/id/id_test.go
==================================================================
--- domain/id/id_test.go
+++ domain/id/id_test.go
@@ -1,87 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-// Package id_test provides unit tests for testing zettel id specific functions.
-package id_test
-
-import (
-	"testing"
-
-	"zettelstore.de/z/domain/id"
-)
-
-func TestIsValid(t *testing.T) {
-	t.Parallel()
-	validIDs := []string{
-		"00000000000001",
-		"00000000000020",
-		"00000000000300",
-		"00000000004000",
-		"00000000050000",
-		"00000000600000",
-		"00000007000000",
-		"00000080000000",
-		"00000900000000",
-		"00001000000000",
-		"00020000000000",
-		"00300000000000",
-		"04000000000000",
-		"50000000000000",
-		"99999999999999",
-		"00001007030200",
-		"20200310195100",
-	}
-
-	for i, sid := range validIDs {
-		zid, err := id.Parse(sid)
-		if err != nil {
-			t.Errorf("i=%d: sid=%q is not valid, but should be. err=%v", i, sid, err)
-		}
-		s := zid.String()
-		if s != sid {
-			t.Errorf(
-				"i=%d: zid=%v does not format to %q, but to %q", i, zid, sid, s)
-		}
-	}
-
-	invalidIDs := []string{
-		"", "0", "a",
-		"00000000000000",
-		"0000000000000a",
-		"000000000000000",
-		"20200310T195100",
-	}
-
-	for i, sid := range invalidIDs {
-		if zid, err := id.Parse(sid); err == nil {
-			t.Errorf("i=%d: sid=%q is valid (zid=%s), but should not be", i, sid, zid)
-		}
-	}
-}
-
-var sResult string // to disable compiler optimization in loop below
-
-func BenchmarkString(b *testing.B) {
-	var s string
-	for n := 0; n < b.N; n++ {
-		s = id.Zid(12345678901200).String()
-	}
-	sResult = s
-}
-
-var bResult []byte // to disable compiler optimization in loop below
-
-func BenchmarkBytes(b *testing.B) {
-	var bs []byte
-	for n := 0; n < b.N; n++ {
-		bs = id.Zid(12345678901200).Bytes()
-	}
-	bResult = bs
-}

DELETED domain/id/set.go
Index: domain/id/set.go
==================================================================
--- domain/id/set.go
+++ domain/id/set.go
@@ -1,119 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2021-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package id
-
-// Set is a set of zettel identifier
-type Set map[Zid]struct{}
-
-// NewSet returns a new set of identifier with the given initial values.
-func NewSet(zids ...Zid) Set {
-	l := len(zids)
-	if l < 8 {
-		l = 8
-	}
-	result := make(Set, l)
-	result.AddSlice(zids)
-	return result
-}
-
-// NewSetCap returns a new set of identifier with the given capacity and initial values.
-func NewSetCap(c int, zids ...Zid) Set {
-	l := len(zids)
-	if c < l {
-		c = l
-	}
-	if c < 8 {
-		c = 8
-	}
-	result := make(Set, c)
-	result.AddSlice(zids)
-	return result
-}
-
-// Zid adds a Zid to the set.
-func (s Set) Zid(zid Zid) Set {
-	if s == nil {
-		return NewSet(zid)
-	}
-	s[zid] = struct{}{}
-	return s
-}
-
-// Contains return true if the set is nil or if the set contains the given Zettel identifier.
-func (s Set) Contains(zid Zid) bool {
-	if s != nil {
-		_, found := s[zid]
-		return found
-	}
-	return true
-}
-
-// Add all member from the other set.
-func (s Set) Add(other Set) Set {
-	if s == nil {
-		return other
-	}
-	for zid := range other {
-		s[zid] = struct{}{}
-	}
-	return s
-}
-
-// AddSlice adds all identifier of the given slice to the set.
-func (s Set) AddSlice(sl Slice) {
-	for _, zid := range sl {
-		s[zid] = struct{}{}
-	}
-}
-
-// Sorted returns the set as a sorted slice of zettel identifier.
-func (s Set) Sorted() Slice {
-	if l := len(s); l > 0 {
-		result := make(Slice, 0, l)
-		for zid := range s {
-			result = append(result, zid)
-		}
-		result.Sort()
-		return result
-	}
-	return nil
-}
-
-// IntersectOrSet removes all zettel identifier that are not in the other set.
-// Both sets can be modified by this method. One of them is the set returned.
-// It contains the intersection of both, if s is not nil.
-//
-// If s == nil, then the other set is always returned.
-func (s Set) IntersectOrSet(other Set) Set {
-	if s == nil {
-		return other
-	}
-	if len(s) > len(other) {
-		s, other = other, s
-	}
-	for zid := range s {
-		_, otherOk := other[zid]
-		if !otherOk {
-			delete(s, zid)
-		}
-	}
-	return s
-}
-
-// Remove all zettel identifier from 's' that are in the set 'other'.
-func (s Set) Remove(other Set) {
-	if s == nil || other == nil {
-		return
-	}
-	for zid := range other {
-		delete(s, zid)
-	}
-}

DELETED domain/id/set_test.go
Index: domain/id/set_test.go
==================================================================
--- domain/id/set_test.go
+++ domain/id/set_test.go
@@ -1,149 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2021-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package id_test
-
-import (
-	"testing"
-
-	"zettelstore.de/z/domain/id"
-)
-
-func TestSetContains(t *testing.T) {
-	t.Parallel()
-	testcases := []struct {
-		s   id.Set
-		zid id.Zid
-		exp bool
-	}{
-		{nil, id.Invalid, true},
-		{nil, 14, true},
-		{id.NewSet(), id.Invalid, false},
-		{id.NewSet(), 1, false},
-		{id.NewSet(), id.Invalid, false},
-		{id.NewSet(1), 1, true},
-	}
-	for i, tc := range testcases {
-		got := tc.s.Contains(tc.zid)
-		if got != tc.exp {
-			t.Errorf("%d: %v.Contains(%v) == %v, but got %v", i, tc.s, tc.zid, tc.exp, got)
-		}
-	}
-}
-
-func TestSetAdd(t *testing.T) {
-	t.Parallel()
-	testcases := []struct {
-		s1, s2 id.Set
-		exp    id.Slice
-	}{
-		{nil, nil, nil},
-		{id.NewSet(), nil, nil},
-		{id.NewSet(), id.NewSet(), nil},
-		{nil, id.NewSet(1), id.Slice{1}},
-		{id.NewSet(1), nil, id.Slice{1}},
-		{id.NewSet(1), id.NewSet(), id.Slice{1}},
-		{id.NewSet(1), id.NewSet(2), id.Slice{1, 2}},
-		{id.NewSet(1), id.NewSet(1), id.Slice{1}},
-	}
-	for i, tc := range testcases {
-		sl1 := tc.s1.Sorted()
-		sl2 := tc.s2.Sorted()
-		got := tc.s1.Add(tc.s2).Sorted()
-		if !got.Equal(tc.exp) {
-			t.Errorf("%d: %v.Add(%v) should be %v, but got %v", i, sl1, sl2, tc.exp, got)
-		}
-	}
-}
-
-func TestSetSorted(t *testing.T) {
-	t.Parallel()
-	testcases := []struct {
-		set id.Set
-		exp id.Slice
-	}{
-		{nil, nil},
-		{id.NewSet(), nil},
-		{id.NewSet(9, 4, 6, 1, 7), id.Slice{1, 4, 6, 7, 9}},
-	}
-	for i, tc := range testcases {
-		got := tc.set.Sorted()
-		if !got.Equal(tc.exp) {
-			t.Errorf("%d: %v.Sorted() should be %v, but got %v", i, tc.set, tc.exp, got)
-		}
-	}
-}
-
-func TestSetIntersectOrSet(t *testing.T) {
-	t.Parallel()
-	testcases := []struct {
-		s1, s2 id.Set
-		exp    id.Slice
-	}{
-		{nil, nil, nil},
-		{id.NewSet(), nil, nil},
-		{nil, id.NewSet(), nil},
-		{id.NewSet(), id.NewSet(), nil},
-		{id.NewSet(1), nil, nil},
-		{nil, id.NewSet(1), id.Slice{1}},
-		{id.NewSet(1), id.NewSet(), nil},
-		{id.NewSet(), id.NewSet(1), nil},
-		{id.NewSet(1), id.NewSet(2), nil},
-		{id.NewSet(2), id.NewSet(1), nil},
-		{id.NewSet(1), id.NewSet(1), id.Slice{1}},
-	}
-	for i, tc := range testcases {
-		sl1 := tc.s1.Sorted()
-		sl2 := tc.s2.Sorted()
-		got := tc.s1.IntersectOrSet(tc.s2).Sorted()
-		if !got.Equal(tc.exp) {
-			t.Errorf("%d: %v.IntersectOrSet(%v) should be %v, but got %v", i, sl1, sl2, tc.exp, got)
-		}
-	}
-}
-
-func TestSetRemove(t *testing.T) {
-	t.Parallel()
-	testcases := []struct {
-		s1, s2 id.Set
-		exp    id.Slice
-	}{
-		{nil, nil, nil},
-		{id.NewSet(), nil, nil},
-		{id.NewSet(), id.NewSet(), nil},
-		{id.NewSet(1), nil, id.Slice{1}},
-		{id.NewSet(1), id.NewSet(), id.Slice{1}},
-		{id.NewSet(1), id.NewSet(2), id.Slice{1}},
-		{id.NewSet(1), id.NewSet(1), id.Slice{}},
-	}
-	for i, tc := range testcases {
-		sl1 := tc.s1.Sorted()
-		sl2 := tc.s2.Sorted()
-		newS1 := id.NewSet(sl1...)
-		newS1.Remove(tc.s2)
-		got := newS1.Sorted()
-		if !got.Equal(tc.exp) {
-			t.Errorf("%d: %v.Remove(%v) should be %v, but got %v", i, sl1, sl2, tc.exp, got)
-		}
-	}
-}
-
-//	func BenchmarkSet(b *testing.B) {
-//		s := id.Set{}
-//		for i := 0; i < b.N; i++ {
-//			s[id.Zid(i)] = true
-//		}
-//	}
-func BenchmarkSet(b *testing.B) {
-	s := id.Set{}
-	for i := 0; i < b.N; i++ {
-		s[id.Zid(i)] = struct{}{}
-	}
-}

DELETED domain/id/slice.go
Index: domain/id/slice.go
==================================================================
--- domain/id/slice.go
+++ domain/id/slice.go
@@ -1,67 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2021-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package id
-
-import (
-	"sort"
-	"strings"
-)
-
-// Slice is a sequence of zettel identifier. A special case is a sorted slice.
-type Slice []Zid
-
-func (zs Slice) Len() int           { return len(zs) }
-func (zs Slice) Less(i, j int) bool { return zs[i] < zs[j] }
-func (zs Slice) Swap(i, j int)      { zs[i], zs[j] = zs[j], zs[i] }
-
-// Sort a slice of Zids.
-func (zs Slice) Sort() { sort.Sort(zs) }
-
-// Copy a zettel identifier slice
-func (zs Slice) Copy() Slice {
-	if zs == nil {
-		return nil
-	}
-	result := make(Slice, len(zs))
-	copy(result, zs)
-	return result
-}
-
-// Equal reports whether zs and other are the same length and contain the samle zettel
-// identifier. A nil argument is equivalent to an empty slice.
-func (zs Slice) Equal(other Slice) bool {
-	if len(zs) != len(other) {
-		return false
-	}
-	if len(zs) == 0 {
-		return true
-	}
-	for i, e := range zs {
-		if e != other[i] {
-			return false
-		}
-	}
-	return true
-}
-
-func (zs Slice) String() string {
-	if len(zs) == 0 {
-		return ""
-	}
-	var sb strings.Builder
-	for i, zid := range zs {
-		if i > 0 {
-			sb.WriteByte(' ')
-		}
-		sb.WriteString(zid.String())
-	}
-	return sb.String()
-}

DELETED domain/id/slice_test.go
Index: domain/id/slice_test.go
==================================================================
--- domain/id/slice_test.go
+++ domain/id/slice_test.go
@@ -1,86 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2021-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package id_test
-
-import (
-	"testing"
-
-	"zettelstore.de/z/domain/id"
-)
-
-func TestSliceSort(t *testing.T) {
-	t.Parallel()
-	zs := id.Slice{9, 4, 6, 1, 7}
-	zs.Sort()
-	exp := id.Slice{1, 4, 6, 7, 9}
-	if !zs.Equal(exp) {
-		t.Errorf("Slice.Sort did not work. Expected %v, got %v", exp, zs)
-	}
-}
-
-func TestCopy(t *testing.T) {
-	t.Parallel()
-	var orig id.Slice
-	got := orig.Copy()
-	if got != nil {
-		t.Errorf("Nil copy resulted in %v", got)
-	}
-	orig = id.Slice{9, 4, 6, 1, 7}
-	got = orig.Copy()
-	if !orig.Equal(got) {
-		t.Errorf("Slice.Copy did not work. Expected %v, got %v", orig, got)
-	}
-}
-
-func TestSliceEqual(t *testing.T) {
-	t.Parallel()
-	testcases := []struct {
-		s1, s2 id.Slice
-		exp    bool
-	}{
-		{nil, nil, true},
-		{nil, id.Slice{}, true},
-		{nil, id.Slice{1}, false},
-		{id.Slice{1}, id.Slice{1}, true},
-		{id.Slice{1}, id.Slice{2}, false},
-		{id.Slice{1, 2}, id.Slice{2, 1}, false},
-		{id.Slice{1, 2}, id.Slice{1, 2}, true},
-	}
-	for i, tc := range testcases {
-		got := tc.s1.Equal(tc.s2)
-		if got != tc.exp {
-			t.Errorf("%d/%v.Equal(%v)==%v, but got %v", i, tc.s1, tc.s2, tc.exp, got)
-		}
-		got = tc.s2.Equal(tc.s1)
-		if got != tc.exp {
-			t.Errorf("%d/%v.Equal(%v)==%v, but got %v", i, tc.s2, tc.s1, tc.exp, got)
-		}
-	}
-}
-
-func TestSliceString(t *testing.T) {
-	t.Parallel()
-	testcases := []struct {
-		in  id.Slice
-		exp string
-	}{
-		{nil, ""},
-		{id.Slice{}, ""},
-		{id.Slice{1}, "00000000000001"},
-		{id.Slice{1, 2}, "00000000000001 00000000000002"},
-	}
-	for i, tc := range testcases {
-		got := tc.in.String()
-		if got != tc.exp {
-			t.Errorf("%d/%v: expected %q, but got %q", i, tc.in, tc.exp, got)
-		}
-	}
-}

DELETED domain/meta/collection.go
Index: domain/meta/collection.go
==================================================================
--- domain/meta/collection.go
+++ domain/meta/collection.go
@@ -1,110 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2022-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package meta
-
-import "sort"
-
-// Arrangement stores metadata within its categories.
-// Typecally a category might be a tag name, a role name, a syntax value.
-type Arrangement map[string][]*Meta
-
-// CreateArrangement by inspecting a given key and use the found
-// value as a category.
-func CreateArrangement(metaList []*Meta, key string) Arrangement {
-	if len(metaList) == 0 {
-		return nil
-	}
-	descr := Type(key)
-	if descr == nil {
-		return nil
-	}
-	if descr.IsSet {
-		return createSetArrangement(metaList, key)
-	}
-	return createSimplearrangement(metaList, key)
-}
-
-func createSetArrangement(metaList []*Meta, key string) Arrangement {
-	a := make(Arrangement)
-	for _, m := range metaList {
-		if vals, ok := m.GetList(key); ok {
-			for _, val := range vals {
-				a[val] = append(a[val], m)
-			}
-		}
-	}
-	return a
-}
-
-func createSimplearrangement(metaList []*Meta, key string) Arrangement {
-	a := make(Arrangement)
-	for _, m := range metaList {
-		if val, ok := m.Get(key); ok && val != "" {
-			a[val] = append(a[val], m)
-		}
-	}
-	return a
-}
-
-// Counted returns the list of categories, together with the number of
-// metadata for each category.
-func (a Arrangement) Counted() CountedCategories {
-	if len(a) == 0 {
-		return nil
-	}
-	result := make(CountedCategories, 0, len(a))
-	for cat, metas := range a {
-		result = append(result, CountedCategory{Name: cat, Count: len(metas)})
-	}
-	return result
-}
-
-// CountedCategory contains of a name and the number how much this name occured
-// somewhere.
-type CountedCategory struct {
-	Name  string
-	Count int
-}
-
-// CountedCategories is the list of CountedCategories.
-// Every name must occur only once.
-type CountedCategories []CountedCategory
-
-// SortByName sorts the list by the name attribute.
-// Since each name must occur only once, two CountedCategories cannot have
-// the same name.
-func (ccs CountedCategories) SortByName() {
-	sort.Slice(ccs, func(i, j int) bool { return ccs[i].Name < ccs[j].Name })
-}
-
-// SortByCount sorts the list by the count attribute, descending.
-// If two counts are equal, elements are sorted by name.
-func (ccs CountedCategories) SortByCount() {
-	sort.Slice(ccs, func(i, j int) bool {
-		iCount, jCount := ccs[i].Count, ccs[j].Count
-		if iCount > jCount {
-			return true
-		}
-		if iCount == jCount {
-			return ccs[i].Name < ccs[j].Name
-		}
-		return false
-	})
-}
-
-// Categories returns just the category names.
-func (ccs CountedCategories) Categories() []string {
-	result := make([]string, len(ccs))
-	for i, cc := range ccs {
-		result[i] = cc.Name
-	}
-	return result
-}

DELETED domain/meta/meta.go
Index: domain/meta/meta.go
==================================================================
--- domain/meta/meta.go
+++ domain/meta/meta.go
@@ -1,423 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-// Package meta provides the domain specific type 'meta'.
-package meta
-
-import (
-	"regexp"
-	"sort"
-	"strings"
-	"unicode"
-	"unicode/utf8"
-
-	"zettelstore.de/c/api"
-	"zettelstore.de/c/maps"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/input"
-	"zettelstore.de/z/strfun"
-)
-
-type keyUsage int
-
-const (
-	_             keyUsage = iota
-	usageUser              // Key will be manipulated by the user
-	usageComputed          // Key is computed by zettelstore
-	usageProperty          // Key is computed and not stored by zettelstore
-)
-
-// DescriptionKey formally describes each supported metadata key.
-type DescriptionKey struct {
-	Name    string
-	Type    *DescriptionType
-	usage   keyUsage
-	Inverse string
-}
-
-// IsComputed returns true, if metadata is computed and not set by the user.
-func (kd *DescriptionKey) IsComputed() bool { return kd.usage >= usageComputed }
-
-// IsProperty returns true, if metadata is a computed property.
-func (kd *DescriptionKey) IsProperty() bool { return kd.usage >= usageProperty }
-
-// IsStoredComputed retruns true, if metadata is computed, but also stored.
-func (kd *DescriptionKey) IsStoredComputed() bool { return kd.usage == usageComputed }
-
-var registeredKeys = make(map[string]*DescriptionKey)
-
-func registerKey(name string, t *DescriptionType, usage keyUsage, inverse string) {
-	if _, ok := registeredKeys[name]; ok {
-		panic("Key '" + name + "' already defined")
-	}
-	if inverse != "" {
-		if t != TypeID && t != TypeIDSet {
-			panic("Inversable key '" + name + "' is not identifier type, but " + t.String())
-		}
-		inv, ok := registeredKeys[inverse]
-		if !ok {
-			panic("Inverse Key '" + inverse + "' not found")
-		}
-		if !inv.IsComputed() {
-			panic("Inverse Key '" + inverse + "' is not computed.")
-		}
-		if inv.Type != TypeIDSet {
-			panic("Inverse Key '" + inverse + "' is not an identifier set, but " + inv.Type.String())
-		}
-	}
-	registeredKeys[name] = &DescriptionKey{name, t, usage, inverse}
-}
-
-// IsComputed returns true, if key denotes a computed metadata key.
-func IsComputed(name string) bool {
-	if kd, ok := registeredKeys[name]; ok {
-		return kd.IsComputed()
-	}
-	return false
-}
-
-// IsProperty returns true, if key denotes a property metadata value.
-func IsProperty(name string) bool {
-	if kd, ok := registeredKeys[name]; ok {
-		return kd.IsProperty()
-	}
-	return false
-}
-
-// IsStoredComputed returns true, if key denotes a computed metadata key that is stored.
-func IsStoredComputed(name string) bool {
-	if kd, ok := registeredKeys[name]; ok {
-		return kd.IsStoredComputed()
-	}
-	return false
-}
-
-// Inverse returns the name of the inverse key.
-func Inverse(name string) string {
-	if kd, ok := registeredKeys[name]; ok {
-		return kd.Inverse
-	}
-	return ""
-}
-
-// GetDescription returns the key description object of the given key name.
-func GetDescription(name string) DescriptionKey {
-	if d, ok := registeredKeys[name]; ok {
-		return *d
-	}
-	return DescriptionKey{Type: Type(name)}
-}
-
-// GetSortedKeyDescriptions delivers all metadata key descriptions as a slice, sorted by name.
-func GetSortedKeyDescriptions() []*DescriptionKey {
-	keys := maps.Keys(registeredKeys)
-	result := make([]*DescriptionKey, 0, len(keys))
-	for _, n := range keys {
-		result = append(result, registeredKeys[n])
-	}
-	return result
-}
-
-// Supported keys.
-func init() {
-	registerKey(api.KeyID, TypeID, usageComputed, "")
-	registerKey(api.KeyTitle, TypeEmpty, usageUser, "")
-	registerKey(api.KeyRole, TypeWord, usageUser, "")
-	registerKey(api.KeyTags, TypeTagSet, usageUser, "")
-	registerKey(api.KeySyntax, TypeWord, usageUser, "")
-
-	// Properties that are inverse keys
-	registerKey(api.KeyFolge, TypeIDSet, usageProperty, "")
-	registerKey(api.KeySuccessors, TypeIDSet, usageProperty, "")
-
-	registerKey(api.KeyAuthor, TypeString, usageUser, "")
-	registerKey(api.KeyBack, TypeIDSet, usageProperty, "")
-	registerKey(api.KeyBackward, TypeIDSet, usageProperty, "")
-	registerKey(api.KeyBoxNumber, TypeNumber, usageProperty, "")
-	registerKey(api.KeyCopyright, TypeString, usageUser, "")
-	registerKey(api.KeyCreated, TypeTimestamp, usageComputed, "")
-	registerKey(api.KeyCredential, TypeCredential, usageUser, "")
-	registerKey(api.KeyDead, TypeIDSet, usageProperty, "")
-	registerKey(api.KeyForward, TypeIDSet, usageProperty, "")
-	registerKey(api.KeyLang, TypeWord, usageUser, "")
-	registerKey(api.KeyLicense, TypeEmpty, usageUser, "")
-	registerKey(api.KeyModified, TypeTimestamp, usageComputed, "")
-	registerKey(api.KeyPrecursor, TypeIDSet, usageUser, api.KeyFolge)
-	registerKey(api.KeyPredecessor, TypeID, usageUser, api.KeySuccessors)
-	registerKey(api.KeyPublished, TypeTimestamp, usageProperty, "")
-	registerKey(api.KeyQuery, TypeEmpty, usageUser, "")
-	registerKey(api.KeyReadOnly, TypeWord, usageUser, "")
-	registerKey(api.KeySummary, TypeZettelmarkup, usageUser, "")
-	registerKey(api.KeyURL, TypeURL, usageUser, "")
-	registerKey(api.KeyUselessFiles, TypeString, usageProperty, "")
-	registerKey(api.KeyUserID, TypeWord, usageUser, "")
-	registerKey(api.KeyUserRole, TypeWord, usageUser, "")
-	registerKey(api.KeyVisibility, TypeWord, usageUser, "")
-}
-
-// NewPrefix is the prefix for metadata key in template zettel for creating new zettel.
-const NewPrefix = "new-"
-
-// Meta contains all meta-data of a zettel.
-type Meta struct {
-	Zid     id.Zid
-	pairs   map[string]string
-	YamlSep bool
-}
-
-// New creates a new chunk for storing metadata.
-func New(zid id.Zid) *Meta {
-	return &Meta{Zid: zid, pairs: make(map[string]string, 5)}
-}
-
-// NewWithData creates metadata object with given data.
-func NewWithData(zid id.Zid, data map[string]string) *Meta {
-	pairs := make(map[string]string, len(data))
-	for k, v := range data {
-		pairs[k] = v
-	}
-	return &Meta{Zid: zid, pairs: pairs}
-}
-
-// Length returns the number of bytes stored for the metadata.
-func (m *Meta) Length() int {
-	if m == nil {
-		return 0
-	}
-	result := 6 // storage needed for Zid
-	for k, v := range m.pairs {
-		result += len(k) + len(v) + 1 // 1 because separator
-	}
-	return result
-}
-
-// Clone returns a new copy of the metadata.
-func (m *Meta) Clone() *Meta {
-	return &Meta{
-		Zid:     m.Zid,
-		pairs:   m.Map(),
-		YamlSep: m.YamlSep,
-	}
-}
-
-// Map returns a copy of the meta data as a string map.
-func (m *Meta) Map() map[string]string {
-	pairs := make(map[string]string, len(m.pairs))
-	for k, v := range m.pairs {
-		pairs[k] = v
-	}
-	return pairs
-}
-
-var reKey = regexp.MustCompile("^[0-9a-z][-0-9a-z]{0,254}$")
-
-// KeyIsValid returns true, the the key is a valid string.
-func KeyIsValid(key string) bool {
-	return reKey.MatchString(key)
-}
-
-// Pair is one key-value-pair of a Zettel meta.
-type Pair struct {
-	Key   string
-	Value string
-}
-
-var firstKeys = []string{api.KeyTitle, api.KeyRole, api.KeyTags, api.KeySyntax}
-var firstKeySet strfun.Set
-
-func init() {
-	firstKeySet = strfun.NewSet(firstKeys...)
-}
-
-// Set stores the given string value under the given key.
-func (m *Meta) Set(key, value string) {
-	if key != api.KeyID {
-		m.pairs[key] = trimValue(value)
-	}
-}
-
-// SetNonEmpty stores the given value under the given key, if the value is non-empty.
-// An empty value will delete the previous association.
-func (m *Meta) SetNonEmpty(key, value string) {
-	if value == "" {
-		delete(m.pairs, key)
-	} else if key != api.KeyID {
-		m.pairs[key] = trimValue(value)
-	}
-}
-
-func trimValue(value string) string {
-	return strings.TrimFunc(value, input.IsSpace)
-}
-
-// Get retrieves the string value of a given key. The bool value signals,
-// whether there was a value stored or not.
-func (m *Meta) Get(key string) (string, bool) {
-	if m == nil {
-		return "", false
-	}
-	if key == api.KeyID {
-		return m.Zid.String(), true
-	}
-	value, ok := m.pairs[key]
-	return value, ok
-}
-
-// GetDefault retrieves the string value of the given key. If no value was
-// stored, the given default value is returned.
-func (m *Meta) GetDefault(key, def string) string {
-	if value, found := m.Get(key); found {
-		return value
-	}
-	return def
-}
-
-// GetTitle returns the title of the metadata. It is the only key that has a
-// defined default value: the string representation of the zettel identifier.
-func (m *Meta) GetTitle() string {
-	if title, found := m.Get(api.KeyTitle); found {
-		return title
-	}
-	return m.Zid.String()
-}
-
-// Pairs returns not computed key/values pairs stored, in a specific order.
-// First come the pairs with predefined keys: MetaTitleKey, MetaTagsKey, MetaSyntaxKey,
-// MetaContextKey. Then all other pairs are append to the list, ordered by key.
-func (m *Meta) Pairs() []Pair {
-	return m.doPairs(m.getFirstKeys(), notComputedKey)
-}
-
-// ComputedPairs returns all key/values pairs stored, in a specific order. First come
-// the pairs with predefined keys: MetaTitleKey, MetaTagsKey, MetaSyntaxKey,
-// MetaContextKey. Then all other pairs are append to the list, ordered by key.
-func (m *Meta) ComputedPairs() []Pair {
-	return m.doPairs(m.getFirstKeys(), anyKey)
-}
-
-// PairsRest returns not computed key/values pairs stored, except the values with
-// predefined keys. The pairs are ordered by key.
-func (m *Meta) PairsRest() []Pair {
-	result := make([]Pair, 0, len(m.pairs))
-	return m.doPairs(result, notComputedKey)
-}
-
-// ComputedPairsRest returns all key/values pairs stored, except the values with
-// predefined keys. The pairs are ordered by key.
-func (m *Meta) ComputedPairsRest() []Pair {
-	result := make([]Pair, 0, len(m.pairs))
-	return m.doPairs(result, anyKey)
-}
-
-func notComputedKey(key string) bool { return !IsComputed(key) }
-func anyKey(string) bool             { return true }
-
-func (m *Meta) doPairs(firstKeys []Pair, addKeyPred func(string) bool) []Pair {
-	keys := m.getKeysRest(addKeyPred)
-	for _, k := range keys {
-		firstKeys = append(firstKeys, Pair{k, m.pairs[k]})
-	}
-	return firstKeys
-}
-
-func (m *Meta) getFirstKeys() []Pair {
-	result := make([]Pair, 0, len(m.pairs))
-	for _, key := range firstKeys {
-		if value, ok := m.pairs[key]; ok {
-			result = append(result, Pair{key, value})
-		}
-	}
-	return result
-}
-
-func (m *Meta) getKeysRest(addKeyPred func(string) bool) []string {
-	keys := make([]string, 0, len(m.pairs))
-	for k := range m.pairs {
-		if !firstKeySet.Has(k) && addKeyPred(k) {
-			keys = append(keys, k)
-		}
-	}
-	sort.Strings(keys)
-	return keys
-}
-
-// Delete removes a key from the data.
-func (m *Meta) Delete(key string) {
-	if key != api.KeyID {
-		delete(m.pairs, key)
-	}
-}
-
-// Equal compares to metas for equality.
-func (m *Meta) Equal(o *Meta, allowComputed bool) bool {
-	if m == nil && o == nil {
-		return true
-	}
-	if m == nil || o == nil || m.Zid != o.Zid {
-		return false
-	}
-	tested := make(strfun.Set, len(m.pairs))
-	for k, v := range m.pairs {
-		tested.Set(k)
-		if !equalValue(k, v, o, allowComputed) {
-			return false
-		}
-	}
-	for k, v := range o.pairs {
-		if !tested.Has(k) && !equalValue(k, v, m, allowComputed) {
-			return false
-		}
-	}
-	return true
-}
-
-func equalValue(key, val string, other *Meta, allowComputed bool) bool {
-	if allowComputed || !IsComputed(key) {
-		if valO, found := other.pairs[key]; !found || val != valO {
-			return false
-		}
-	}
-	return true
-}
-
-// Sanitize all metadata keys and values, so that they can be written safely into a file.
-func (m *Meta) Sanitize() {
-	if m == nil {
-		return
-	}
-	for k, v := range m.pairs {
-		m.pairs[RemoveNonGraphic(k)] = RemoveNonGraphic(v)
-	}
-}
-
-// RemoveNonGraphic changes the given string not to include non-graphical characters.
-// It is needed to sanitize meta data.
-func RemoveNonGraphic(s string) string {
-	if s == "" {
-		return ""
-	}
-	pos := 0
-	var sb strings.Builder
-	for pos < len(s) {
-		nextPos := strings.IndexFunc(s[pos:], func(r rune) bool { return !unicode.IsGraphic(r) })
-		if nextPos < 0 {
-			break
-		}
-		sb.WriteString(s[pos:nextPos])
-		sb.WriteByte(' ')
-		_, size := utf8.DecodeRuneInString(s[nextPos:])
-		pos = nextPos + size
-	}
-	if pos == 0 {
-		return strings.TrimSpace(s)
-	}
-	sb.WriteString(s[pos:])
-	return strings.TrimSpace(sb.String())
-}

DELETED domain/meta/meta_test.go
Index: domain/meta/meta_test.go
==================================================================
--- domain/meta/meta_test.go
+++ domain/meta/meta_test.go
@@ -1,262 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-// Package meta_test provides tests for the domain specific type 'meta'.
-package meta
-
-import (
-	"strings"
-	"testing"
-
-	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-)
-
-const testID = id.Zid(98765432101234)
-
-func TestKeyIsValid(t *testing.T) {
-	t.Parallel()
-	validKeys := []string{"0", "a", "0-", "title", "title-----", strings.Repeat("r", 255)}
-	for _, key := range validKeys {
-		if !KeyIsValid(key) {
-			t.Errorf("Key %q wrongly identified as invalid key", key)
-		}
-	}
-	invalidKeys := []string{"", "-", "-a", "Title", "a_b", strings.Repeat("e", 256)}
-	for _, key := range invalidKeys {
-		if KeyIsValid(key) {
-			t.Errorf("Key %q wrongly identified as valid key", key)
-		}
-	}
-}
-
-func TestTitleHeader(t *testing.T) {
-	t.Parallel()
-	m := New(testID)
-	if got, ok := m.Get(api.KeyTitle); ok && got != "" {
-		t.Errorf("Title is not empty, but %q", got)
-	}
-	addToMeta(m, api.KeyTitle, " ")
-	if got, ok := m.Get(api.KeyTitle); ok && got != "" {
-		t.Errorf("Title is not empty, but %q", got)
-	}
-	const st = "A simple text"
-	addToMeta(m, api.KeyTitle, " "+st+"  ")
-	if got, ok := m.Get(api.KeyTitle); !ok || got != st {
-		t.Errorf("Title is not %q, but %q", st, got)
-	}
-	addToMeta(m, api.KeyTitle, "  "+st+"\t")
-	const exp = st + " " + st
-	if got, ok := m.Get(api.KeyTitle); !ok || got != exp {
-		t.Errorf("Title is not %q, but %q", exp, got)
-	}
-
-	m = New(testID)
-	const at = "A Title"
-	addToMeta(m, api.KeyTitle, at)
-	addToMeta(m, api.KeyTitle, " ")
-	if got, ok := m.Get(api.KeyTitle); !ok || got != at {
-		t.Errorf("Title is not %q, but %q", at, got)
-	}
-}
-
-func checkSet(t *testing.T, exp []string, m *Meta, key string) {
-	t.Helper()
-	got, _ := m.GetList(key)
-	for i, tag := range exp {
-		if i < len(got) {
-			if tag != got[i] {
-				t.Errorf("Pos=%d, expected %q, got %q", i, exp[i], got[i])
-			}
-		} else {
-			t.Errorf("Expected %q, but is missing", exp[i])
-		}
-	}
-	if len(exp) < len(got) {
-		t.Errorf("Extra tags: %q", got[len(exp):])
-	}
-}
-
-func TestTagsHeader(t *testing.T) {
-	t.Parallel()
-	m := New(testID)
-	checkSet(t, []string{}, m, api.KeyTags)
-
-	addToMeta(m, api.KeyTags, "")
-	checkSet(t, []string{}, m, api.KeyTags)
-
-	addToMeta(m, api.KeyTags, "  #t1 #t2  #t3 #t4  ")
-	checkSet(t, []string{"#t1", "#t2", "#t3", "#t4"}, m, api.KeyTags)
-
-	addToMeta(m, api.KeyTags, "#t5")
-	checkSet(t, []string{"#t1", "#t2", "#t3", "#t4", "#t5"}, m, api.KeyTags)
-
-	addToMeta(m, api.KeyTags, "t6")
-	checkSet(t, []string{"#t1", "#t2", "#t3", "#t4", "#t5"}, m, api.KeyTags)
-}
-
-func TestSyntax(t *testing.T) {
-	t.Parallel()
-	m := New(testID)
-	if got, ok := m.Get(api.KeySyntax); ok || got != "" {
-		t.Errorf("Syntax is not %q, but %q", "", got)
-	}
-	addToMeta(m, api.KeySyntax, " ")
-	if got, _ := m.Get(api.KeySyntax); got != "" {
-		t.Errorf("Syntax is not %q, but %q", "", got)
-	}
-	addToMeta(m, api.KeySyntax, "MarkDown")
-	const exp = "markdown"
-	if got, ok := m.Get(api.KeySyntax); !ok || got != exp {
-		t.Errorf("Syntax is not %q, but %q", exp, got)
-	}
-	addToMeta(m, api.KeySyntax, " ")
-	if got, _ := m.Get(api.KeySyntax); got != "" {
-		t.Errorf("Syntax is not %q, but %q", "", got)
-	}
-}
-
-func checkHeader(t *testing.T, exp map[string]string, gotP []Pair) {
-	t.Helper()
-	got := make(map[string]string, len(gotP))
-	for _, p := range gotP {
-		got[p.Key] = p.Value
-		if _, ok := exp[p.Key]; !ok {
-			t.Errorf("Key %q is not expected, but has value %q", p.Key, p.Value)
-		}
-	}
-	for k, v := range exp {
-		if gv, ok := got[k]; !ok || v != gv {
-			if ok {
-				t.Errorf("Key %q is not %q, but %q", k, v, got[k])
-			} else {
-				t.Errorf("Key %q missing, should have value %q", k, v)
-			}
-		}
-	}
-}
-
-func TestDefaultHeader(t *testing.T) {
-	t.Parallel()
-	m := New(testID)
-	addToMeta(m, "h1", "d1")
-	addToMeta(m, "H2", "D2")
-	addToMeta(m, "H1", "D1.1")
-	exp := map[string]string{"h1": "d1 D1.1", "h2": "D2"}
-	checkHeader(t, exp, m.Pairs())
-	addToMeta(m, "", "d0")
-	checkHeader(t, exp, m.Pairs())
-	addToMeta(m, "h3", "")
-	exp["h3"] = ""
-	checkHeader(t, exp, m.Pairs())
-	addToMeta(m, "h3", "  ")
-	checkHeader(t, exp, m.Pairs())
-	addToMeta(m, "h4", " ")
-	exp["h4"] = ""
-	checkHeader(t, exp, m.Pairs())
-}
-
-func TestDelete(t *testing.T) {
-	t.Parallel()
-	m := New(testID)
-	m.Set("key", "val")
-	if got, ok := m.Get("key"); !ok || got != "val" {
-		t.Errorf("Value != %q, got: %v/%q", "val", ok, got)
-	}
-	m.Set("key", "")
-	if got, ok := m.Get("key"); !ok || got != "" {
-		t.Errorf("Value != %q, got: %v/%q", "", ok, got)
-	}
-	m.Delete("key")
-	if got, ok := m.Get("key"); ok || got != "" {
-		t.Errorf("Value != %q, got: %v/%q", "", ok, got)
-	}
-}
-
-func TestEqual(t *testing.T) {
-	t.Parallel()
-	testcases := []struct {
-		pairs1, pairs2 []string
-		allowComputed  bool
-		exp            bool
-	}{
-		{nil, nil, true, true},
-		{nil, nil, false, true},
-		{[]string{"a", "a"}, nil, false, false},
-		{[]string{"a", "a"}, nil, true, false},
-		{[]string{api.KeyFolge, "0"}, nil, true, false},
-		{[]string{api.KeyFolge, "0"}, nil, false, true},
-		{[]string{api.KeyFolge, "0"}, []string{api.KeyFolge, "0"}, true, true},
-		{[]string{api.KeyFolge, "0"}, []string{api.KeyFolge, "0"}, false, true},
-	}
-	for i, tc := range testcases {
-		m1 := pairs2meta(tc.pairs1)
-		m2 := pairs2meta(tc.pairs2)
-		got := m1.Equal(m2, tc.allowComputed)
-		if tc.exp != got {
-			t.Errorf("%d: %v =?= %v: expected=%v, but got=%v", i, tc.pairs1, tc.pairs2, tc.exp, got)
-		}
-		got = m2.Equal(m1, tc.allowComputed)
-		if tc.exp != got {
-			t.Errorf("%d: %v =!= %v: expected=%v, but got=%v", i, tc.pairs1, tc.pairs2, tc.exp, got)
-		}
-	}
-
-	// Pathologic cases
-	var m1, m2 *Meta
-	if !m1.Equal(m2, true) {
-		t.Error("Nil metas should be treated equal")
-	}
-	m1 = New(testID)
-	if m1.Equal(m2, true) {
-		t.Error("Empty meta should not be equal to nil")
-	}
-	if m2.Equal(m1, true) {
-		t.Error("Nil meta should should not be equal to empty")
-	}
-	m2 = New(testID + 1)
-	if m1.Equal(m2, true) {
-		t.Error("Different ID should differentiate")
-	}
-	if m2.Equal(m1, true) {
-		t.Error("Different ID should differentiate")
-	}
-}
-
-func pairs2meta(pairs []string) *Meta {
-	m := New(testID)
-	for i := 0; i < len(pairs); i = i + 2 {
-		m.Set(pairs[i], pairs[i+1])
-	}
-	return m
-}
-
-func TestRemoveNonGraphic(t *testing.T) {
-	testCases := []struct {
-		inp string
-		exp string
-	}{
-		{"", ""},
-		{" ", ""},
-		{"a", "a"},
-		{"a ", "a"},
-		{"a b", "a b"},
-		{"\n", ""},
-		{"a\n", "a"},
-		{"a\nb", "a b"},
-		{"a\tb", "a b"},
-	}
-	for i, tc := range testCases {
-		got := RemoveNonGraphic(tc.inp)
-		if tc.exp != got {
-			t.Errorf("%q/%d: expected %q, but got %q", tc.inp, i, tc.exp, got)
-		}
-	}
-}

DELETED domain/meta/parse.go
Index: domain/meta/parse.go
==================================================================
--- domain/meta/parse.go
+++ domain/meta/parse.go
@@ -1,177 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package meta
-
-import (
-	"strings"
-
-	"zettelstore.de/c/api"
-	"zettelstore.de/c/maps"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/input"
-	"zettelstore.de/z/strfun"
-)
-
-// NewFromInput parses the meta data of a zettel.
-func NewFromInput(zid id.Zid, inp *input.Input) *Meta {
-	if inp.Ch == '-' && inp.PeekN(0) == '-' && inp.PeekN(1) == '-' {
-		skipToEOL(inp)
-		inp.EatEOL()
-	}
-	meta := New(zid)
-	for {
-		skipSpace(inp)
-		switch inp.Ch {
-		case '\r':
-			if inp.Peek() == '\n' {
-				inp.Next()
-			}
-			fallthrough
-		case '\n':
-			inp.Next()
-			return meta
-		case input.EOS:
-			return meta
-		case '%':
-			skipToEOL(inp)
-			inp.EatEOL()
-			continue
-		}
-		parseHeader(meta, inp)
-		if inp.Ch == '-' && inp.PeekN(0) == '-' && inp.PeekN(1) == '-' {
-			skipToEOL(inp)
-			inp.EatEOL()
-			meta.YamlSep = true
-			return meta
-		}
-	}
-}
-
-func parseHeader(m *Meta, inp *input.Input) {
-	pos := inp.Pos
-	for isHeader(inp.Ch) {
-		inp.Next()
-	}
-	key := inp.Src[pos:inp.Pos]
-	skipSpace(inp)
-	if inp.Ch == ':' {
-		inp.Next()
-	}
-	var val []byte
-	for {
-		skipSpace(inp)
-		pos = inp.Pos
-		skipToEOL(inp)
-		val = append(val, inp.Src[pos:inp.Pos]...)
-		inp.EatEOL()
-		if !input.IsSpace(inp.Ch) {
-			break
-		}
-		val = append(val, ' ')
-	}
-	addToMeta(m, string(key), string(val))
-}
-
-func skipSpace(inp *input.Input) {
-	for input.IsSpace(inp.Ch) {
-		inp.Next()
-	}
-}
-
-func skipToEOL(inp *input.Input) {
-	for {
-		switch inp.Ch {
-		case '\n', '\r', input.EOS:
-			return
-		}
-		inp.Next()
-	}
-}
-
-// Return true iff rune is valid for header key.
-func isHeader(ch rune) bool {
-	return ('a' <= ch && ch <= 'z') ||
-		('0' <= ch && ch <= '9') ||
-		ch == '-' ||
-		('A' <= ch && ch <= 'Z')
-}
-
-type predValidElem func(string) bool
-
-func addToSet(set strfun.Set, elems []string, useElem predValidElem) {
-	for _, s := range elems {
-		if len(s) > 0 && useElem(s) {
-			set.Set(s)
-		}
-	}
-}
-
-func addSet(m *Meta, key, val string, useElem predValidElem) {
-	newElems := strings.Fields(val)
-	oldElems, ok := m.GetList(key)
-	if !ok {
-		oldElems = nil
-	}
-
-	set := make(strfun.Set, len(newElems)+len(oldElems))
-	addToSet(set, newElems, useElem)
-	if len(set) == 0 {
-		// Nothing to add. Maybe because of rejected elements.
-		return
-	}
-	addToSet(set, oldElems, useElem)
-	m.SetList(key, maps.Keys(set))
-}
-
-func addData(m *Meta, k, v string) {
-	if o, ok := m.Get(k); !ok || o == "" {
-		m.Set(k, v)
-	} else if v != "" {
-		m.Set(k, o+" "+v)
-	}
-}
-
-func addToMeta(m *Meta, key, val string) {
-	v := trimValue(val)
-	key = strings.ToLower(key)
-	if !KeyIsValid(key) {
-		return
-	}
-	switch key {
-	case "", api.KeyID:
-		// Empty key and 'id' key will be ignored
-		return
-	}
-
-	switch Type(key) {
-	case TypeTagSet:
-		addSet(m, key, strings.ToLower(v), func(s string) bool { return s[0] == '#' && len(s) > 1 })
-	case TypeWord:
-		m.Set(key, strings.ToLower(v))
-	case TypeWordSet:
-		addSet(m, key, strings.ToLower(v), func(s string) bool { return true })
-	case TypeID:
-		if _, err := id.Parse(v); err == nil {
-			m.Set(key, v)
-		}
-	case TypeIDSet:
-		addSet(m, key, v, func(s string) bool {
-			_, err := id.Parse(s)
-			return err == nil
-		})
-	case TypeTimestamp:
-		if _, ok := TimeValue(v); ok {
-			m.Set(key, v)
-		}
-	default:
-		addData(m, key, v)
-	}
-}

DELETED domain/meta/parse_test.go
Index: domain/meta/parse_test.go
==================================================================
--- domain/meta/parse_test.go
+++ domain/meta/parse_test.go
@@ -1,167 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package meta_test
-
-import (
-	"strings"
-	"testing"
-
-	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/meta"
-	"zettelstore.de/z/input"
-)
-
-func parseMetaStr(src string) *meta.Meta {
-	return meta.NewFromInput(testID, input.NewInput([]byte(src)))
-}
-
-func TestEmpty(t *testing.T) {
-	t.Parallel()
-	m := parseMetaStr("")
-	if got, ok := m.Get(api.KeySyntax); ok || got != "" {
-		t.Errorf("Syntax is not %q, but %q", "", got)
-	}
-	if got, ok := m.GetList(api.KeyTags); ok || len(got) > 0 {
-		t.Errorf("Tags are not nil, but %v", got)
-	}
-}
-
-func TestTitle(t *testing.T) {
-	t.Parallel()
-	td := []struct{ s, e string }{
-		{api.KeyTitle + ": a title", "a title"},
-		{api.KeyTitle + ": a\n\t title", "a title"},
-		{api.KeyTitle + ": a\n\t title\r\n  x", "a title x"},
-		{api.KeyTitle + " AbC", "AbC"},
-		{api.KeyTitle + " AbC\n ded", "AbC ded"},
-		{api.KeyTitle + ": o\ntitle: p", "o p"},
-		{api.KeyTitle + ": O\n\ntitle: P", "O"},
-		{api.KeyTitle + ": b\r\ntitle: c", "b c"},
-		{api.KeyTitle + ": B\r\n\r\ntitle: C", "B"},
-		{api.KeyTitle + ": r\rtitle: q", "r q"},
-		{api.KeyTitle + ": R\r\rtitle: Q", "R"},
-	}
-	for i, tc := range td {
-		m := parseMetaStr(tc.s)
-		if got, ok := m.Get(api.KeyTitle); !ok || got != tc.e {
-			t.Log(m)
-			t.Errorf("TC=%d: expected %q, got %q", i, tc.e, got)
-		}
-	}
-}
-
-func TestTags(t *testing.T) {
-	t.Parallel()
-	testcases := []struct {
-		src string
-		exp string
-	}{
-		{"", ""},
-		{api.KeyTags + ":", ""},
-		{api.KeyTags + ": c", ""},
-		{api.KeyTags + ": #", ""},
-		{api.KeyTags + ": #c", "c"},
-		{api.KeyTags + ": #c #", "c"},
-		{api.KeyTags + ": #c #b", "b c"},
-		{api.KeyTags + ": #c # #", "c"},
-		{api.KeyTags + ": #c # #b", "b c"},
-	}
-	for i, tc := range testcases {
-		m := parseMetaStr(tc.src)
-		tags, found := m.GetTags(api.KeyTags)
-		if !found {
-			if tc.exp != "" {
-				t.Errorf("%d / %q: no %s found", i, tc.src, api.KeyTags)
-			}
-			continue
-		}
-		if tc.exp == "" && len(tags) > 0 {
-			t.Errorf("%d / %q: expected no %s, but got %v", i, tc.src, api.KeyTags, tags)
-			continue
-		}
-		got := strings.Join(tags, " ")
-		if tc.exp != got {
-			t.Errorf("%d / %q: expected %q, got: %q", i, tc.src, tc.exp, got)
-		}
-	}
-}
-
-func TestNewFromInput(t *testing.T) {
-	t.Parallel()
-	testcases := []struct {
-		input string
-		exp   []meta.Pair
-	}{
-		{"", []meta.Pair{}},
-		{" a:b", []meta.Pair{{"a", "b"}}},
-		{"%a:b", []meta.Pair{}},
-		{"a:b\r\n\r\nc:d", []meta.Pair{{"a", "b"}}},
-		{"a:b\r\n%c:d", []meta.Pair{{"a", "b"}}},
-		{"% a:b\r\n c:d", []meta.Pair{{"c", "d"}}},
-		{"---\r\na:b\r\n", []meta.Pair{{"a", "b"}}},
-		{"---\r\na:b\r\n--\r\nc:d", []meta.Pair{{"a", "b"}, {"c", "d"}}},
-		{"---\r\na:b\r\n---\r\nc:d", []meta.Pair{{"a", "b"}}},
-		{"---\r\na:b\r\n----\r\nc:d", []meta.Pair{{"a", "b"}}},
-		{"new-title:\nnew-url:", []meta.Pair{{"new-title", ""}, {"new-url", ""}}},
-	}
-	for i, tc := range testcases {
-		meta := parseMetaStr(tc.input)
-		if got := meta.Pairs(); !equalPairs(tc.exp, got) {
-			t.Errorf("TC=%d: expected=%v, got=%v", i, tc.exp, got)
-		}
-	}
-
-	// Test, whether input position is correct.
-	inp := input.NewInput([]byte("---\na:b\n---\nX"))
-	m := meta.NewFromInput(testID, inp)
-	exp := []meta.Pair{{"a", "b"}}
-	if got := m.Pairs(); !equalPairs(exp, got) {
-		t.Errorf("Expected=%v, got=%v", exp, got)
-	}
-	expCh := 'X'
-	if gotCh := inp.Ch; gotCh != expCh {
-		t.Errorf("Expected=%v, got=%v", expCh, gotCh)
-	}
-}
-
-func equalPairs(one, two []meta.Pair) bool {
-	if len(one) != len(two) {
-		return false
-	}
-	for i := 0; i < len(one); i++ {
-		if one[i].Key != two[i].Key || one[i].Value != two[i].Value {
-			return false
-		}
-	}
-	return true
-}
-
-func TestPrecursorIDSet(t *testing.T) {
-	t.Parallel()
-	var testdata = []struct {
-		inp string
-		exp string
-	}{
-		{"", ""},
-		{"123", ""},
-		{"12345678901234", "12345678901234"},
-		{"123 12345678901234", "12345678901234"},
-		{"12345678901234 123", "12345678901234"},
-		{"01234567890123 123 12345678901234", "01234567890123 12345678901234"},
-		{"12345678901234 01234567890123", "01234567890123 12345678901234"},
-	}
-	for i, tc := range testdata {
-		m := parseMetaStr(api.KeyPrecursor + ": " + tc.inp)
-		if got, ok := m.Get(api.KeyPrecursor); (!ok && tc.exp != "") || tc.exp != got {
-			t.Errorf("TC=%d: expected %q, but got %q when parsing %q", i, tc.exp, got, tc.inp)
-		}
-	}
-}

DELETED domain/meta/type.go
Index: domain/meta/type.go
==================================================================
--- domain/meta/type.go
+++ domain/meta/type.go
@@ -1,207 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package meta
-
-import (
-	"strconv"
-	"strings"
-	"sync"
-	"time"
-
-	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-)
-
-// DescriptionType is a description of a specific key type.
-type DescriptionType struct {
-	Name  string
-	IsSet bool
-}
-
-// String returns the string representation of the given type
-func (t DescriptionType) String() string { return t.Name }
-
-var registeredTypes = make(map[string]*DescriptionType)
-
-func registerType(name string, isSet bool) *DescriptionType {
-	if _, ok := registeredTypes[name]; ok {
-		panic("Type '" + name + "' already registered")
-	}
-	t := &DescriptionType{name, isSet}
-	registeredTypes[name] = t
-	return t
-}
-
-// Supported key types.
-var (
-	TypeCredential   = registerType(api.MetaCredential, false)
-	TypeEmpty        = registerType(api.MetaEmpty, false)
-	TypeID           = registerType(api.MetaID, false)
-	TypeIDSet        = registerType(api.MetaIDSet, true)
-	TypeNumber       = registerType(api.MetaNumber, false)
-	TypeString       = registerType(api.MetaString, false)
-	TypeTagSet       = registerType(api.MetaTagSet, true)
-	TypeTimestamp    = registerType(api.MetaTimestamp, false)
-	TypeURL          = registerType(api.MetaURL, false)
-	TypeWord         = registerType(api.MetaWord, false)
-	TypeWordSet      = registerType(api.MetaWordSet, true)
-	TypeZettelmarkup = registerType(api.MetaZettelmarkup, false)
-)
-
-// Type returns a type hint for the given key. If no type hint is specified,
-// TypeUnknown is returned.
-func (*Meta) Type(key string) *DescriptionType {
-	return Type(key)
-}
-
-var (
-	cachedTypedKeys = make(map[string]*DescriptionType)
-	mxTypedKey      sync.RWMutex
-	suffixTypes     = map[string]*DescriptionType{
-		"-number": TypeNumber,
-		"-role":   TypeWord,
-		"-set":    TypeWordSet,
-		"-title":  TypeZettelmarkup,
-		"-url":    TypeURL,
-		"-zettel": TypeID,
-		"-zid":    TypeID,
-		"-zids":   TypeIDSet,
-	}
-)
-
-// Type returns a type hint for the given key. If no type hint is specified,
-// TypeEmpty is returned.
-func Type(key string) *DescriptionType {
-	if k, ok := registeredKeys[key]; ok {
-		return k.Type
-	}
-	mxTypedKey.RLock()
-	k, ok := cachedTypedKeys[key]
-	mxTypedKey.RUnlock()
-	if ok {
-		return k
-	}
-	for suffix, t := range suffixTypes {
-		if strings.HasSuffix(key, suffix) {
-			mxTypedKey.Lock()
-			defer mxTypedKey.Unlock()
-			cachedTypedKeys[key] = t
-			return t
-		}
-	}
-	return TypeEmpty
-}
-
-// SetList stores the given string list value under the given key.
-func (m *Meta) SetList(key string, values []string) {
-	if key != api.KeyID {
-		for i, val := range values {
-			values[i] = trimValue(val)
-		}
-		m.pairs[key] = strings.Join(values, " ")
-	}
-}
-
-// SetNow stores the current timestamp under the given key.
-func (m *Meta) SetNow(key string) {
-	m.Set(key, time.Now().Local().Format(id.ZidLayout))
-}
-
-// BoolValue returns the value interpreted as a bool.
-func BoolValue(value string) bool {
-	if len(value) > 0 {
-		switch value[0] {
-		case '0', 'f', 'F', 'n', 'N':
-			return false
-		}
-	}
-	return true
-}
-
-// GetBool returns the boolean value of the given key.
-func (m *Meta) GetBool(key string) bool {
-	if value, ok := m.Get(key); ok {
-		return BoolValue(value)
-	}
-	return false
-}
-
-// TimeValue returns the time value of the given value.
-func TimeValue(value string) (time.Time, bool) {
-	if t, err := time.Parse(id.ZidLayout, value); err == nil {
-		return t, true
-	}
-	return time.Time{}, false
-}
-
-// GetTime returns the time value of the given key.
-func (m *Meta) GetTime(key string) (time.Time, bool) {
-	if value, ok := m.Get(key); ok {
-		return TimeValue(value)
-	}
-	return time.Time{}, false
-}
-
-// ListFromValue transforms a string value into a list value.
-func ListFromValue(value string) []string {
-	return strings.Fields(value)
-}
-
-// GetList retrieves the string list value of a given key. The bool value
-// signals, whether there was a value stored or not.
-func (m *Meta) GetList(key string) ([]string, bool) {
-	value, ok := m.Get(key)
-	if !ok {
-		return nil, false
-	}
-	return ListFromValue(value), true
-}
-
-// GetTags returns the list of tags as a string list. Each tag does not begin
-// with the '#' character, in contrast to `GetList`.
-func (m *Meta) GetTags(key string) ([]string, bool) {
-	tagsValue, ok := m.Get(key)
-	if !ok {
-		return nil, false
-	}
-	tags := ListFromValue(strings.ToLower(tagsValue))
-	for i, tag := range tags {
-		tags[i] = CleanTag(tag)
-	}
-	return tags, len(tags) > 0
-}
-
-// CleanTag removes the number character ('#') from a tag value and lowercases it.
-func CleanTag(tag string) string {
-	if len(tag) > 1 && tag[0] == '#' {
-		return tag[1:]
-	}
-	return tag
-}
-
-// GetListOrNil retrieves the string list value of a given key. If there was
-// nothing stores, a nil list is returned.
-func (m *Meta) GetListOrNil(key string) []string {
-	if value, ok := m.GetList(key); ok {
-		return value
-	}
-	return nil
-}
-
-// GetNumber retrieves the numeric value of a given key.
-func (m *Meta) GetNumber(key string, def int64) int64 {
-	if value, ok := m.Get(key); ok {
-		if num, err := strconv.ParseInt(value, 10, 64); err == nil {
-			return num
-		}
-	}
-	return def
-}

DELETED domain/meta/type_test.go
Index: domain/meta/type_test.go
==================================================================
--- domain/meta/type_test.go
+++ domain/meta/type_test.go
@@ -1,64 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package meta_test
-
-import (
-	"strconv"
-	"testing"
-	"time"
-
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
-)
-
-func TestNow(t *testing.T) {
-	t.Parallel()
-	m := meta.New(id.Invalid)
-	m.SetNow("key")
-	val, ok := m.Get("key")
-	if !ok {
-		t.Error("Unable to get value of key")
-	}
-	if len(val) != 14 {
-		t.Errorf("Value is not 14 digits long: %q", val)
-	}
-	if _, err := strconv.ParseInt(val, 10, 64); err != nil {
-		t.Errorf("Unable to parse %q as an int64: %v", val, err)
-	}
-	if _, ok = m.GetTime("key"); !ok {
-		t.Errorf("Unable to get time from value %q", val)
-	}
-}
-
-func TestGetTime(t *testing.T) {
-	t.Parallel()
-	testCases := []struct {
-		value string
-		valid bool
-		exp   time.Time
-	}{
-		{"", false, time.Time{}},
-		{"1", false, time.Time{}},
-		{"00000000000000", false, time.Time{}},
-		{"98765432109876", false, time.Time{}},
-		{"20201221111905", true, time.Date(2020, time.December, 21, 11, 19, 5, 0, time.UTC)},
-	}
-	for i, tc := range testCases {
-		got, ok := meta.TimeValue(tc.value)
-		if ok != tc.valid {
-			t.Errorf("%d: parsing of %q should be %v, but got %v", i, tc.value, tc.valid, ok)
-			continue
-		}
-		if got != tc.exp {
-			t.Errorf("%d: parsing of %q should return %v, but got %v", i, tc.value, tc.exp, got)
-		}
-	}
-}

DELETED domain/meta/values.go
Index: domain/meta/values.go
==================================================================
--- domain/meta/values.go
+++ domain/meta/values.go
@@ -1,110 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package meta
-
-import (
-	"fmt"
-
-	"zettelstore.de/c/api"
-)
-
-// Supported syntax values.
-const (
-	SyntaxCSS      = api.ValueSyntaxCSS
-	SyntaxDraw     = api.ValueSyntaxDraw
-	SyntaxGif      = api.ValueSyntaxGif
-	SyntaxHTML     = api.ValueSyntaxHTML
-	SyntaxJPEG     = "jpeg"
-	SyntaxJPG      = "jpg"
-	SyntaxMarkdown = api.ValueSyntaxMarkdown
-	SyntaxMD       = api.ValueSyntaxMD
-	SyntaxMustache = api.ValueSyntaxMustache
-	SyntaxNone     = api.ValueSyntaxNone
-	SyntaxPlain    = "plain"
-	SyntaxPNG      = "png"
-	SyntaxSVG      = api.ValueSyntaxSVG
-	SyntaxText     = api.ValueSyntaxText
-	SyntaxTxt      = "txt"
-	SyntaxWebp     = "webp"
-	SyntaxZmk      = api.ValueSyntaxZmk
-)
-
-// Visibility enumerates the variations of the 'visibility' meta key.
-type Visibility int
-
-// Supported values for visibility.
-const (
-	_ Visibility = iota
-	VisibilityUnknown
-	VisibilityPublic
-	VisibilityCreator
-	VisibilityLogin
-	VisibilityOwner
-	VisibilityExpert
-)
-
-var visMap = map[string]Visibility{
-	api.ValueVisibilityPublic:  VisibilityPublic,
-	api.ValueVisibilityCreator: VisibilityCreator,
-	api.ValueVisibilityLogin:   VisibilityLogin,
-	api.ValueVisibilityOwner:   VisibilityOwner,
-	api.ValueVisibilityExpert:  VisibilityExpert,
-}
-var revVisMap = map[Visibility]string{}
-
-func init() {
-	for k, v := range visMap {
-		revVisMap[v] = k
-	}
-}
-
-// GetVisibility returns the visibility value of the given string
-func GetVisibility(val string) Visibility {
-	if vis, ok := visMap[val]; ok {
-		return vis
-	}
-	return VisibilityUnknown
-}
-
-func (v Visibility) String() string {
-	if s, ok := revVisMap[v]; ok {
-		return s
-	}
-	return fmt.Sprintf("Unknown (%d)", v)
-}
-
-// UserRole enumerates the supported values of meta key 'user-role'.
-type UserRole int
-
-// Supported values for user roles.
-const (
-	_ UserRole = iota
-	UserRoleUnknown
-	UserRoleCreator
-	UserRoleReader
-	UserRoleWriter
-	UserRoleOwner
-)
-
-var urMap = map[string]UserRole{
-	api.ValueUserRoleCreator: UserRoleCreator,
-	api.ValueUserRoleReader:  UserRoleReader,
-	api.ValueUserRoleWriter:  UserRoleWriter,
-	api.ValueUserRoleOwner:   UserRoleOwner,
-}
-
-// GetUserRole role returns the user role of the given string.
-func GetUserRole(val string) UserRole {
-	if ur, ok := urMap[val]; ok {
-		return ur
-	}
-	return UserRoleUnknown
-}

DELETED domain/meta/write.go
Index: domain/meta/write.go
==================================================================
--- domain/meta/write.go
+++ domain/meta/write.go
@@ -1,57 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package meta
-
-import "io"
-
-// Write writes metadata to a writer, excluding computed and propery values.
-func (m *Meta) Write(w io.Writer) (int, error) {
-	return m.doWrite(w, IsComputed)
-}
-
-// WriteComputed writes metadata to a writer, including computed values,
-// but excluding property values.
-func (m *Meta) WriteComputed(w io.Writer) (int, error) {
-	return m.doWrite(w, IsProperty)
-}
-
-func (m *Meta) doWrite(w io.Writer, ignoreKeyPred func(string) bool) (length int, err error) {
-	for _, p := range m.ComputedPairs() {
-		key := p.Key
-		if ignoreKeyPred(key) {
-			continue
-		}
-		if err != nil {
-			break
-		}
-		var l int
-		l, err = io.WriteString(w, key)
-		length += l
-		if err == nil {
-			l, err = w.Write(colonSpace)
-			length += l
-		}
-		if err == nil {
-			l, err = io.WriteString(w, p.Value)
-			length += l
-		}
-		if err == nil {
-			l, err = w.Write(newline)
-			length += l
-		}
-	}
-	return length, err
-}
-
-var (
-	colonSpace = []byte{':', ' '}
-	newline    = []byte{'\n'}
-)

DELETED domain/meta/write_test.go
Index: domain/meta/write_test.go
==================================================================
--- domain/meta/write_test.go
+++ domain/meta/write_test.go
@@ -1,57 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package meta_test
-
-import (
-	"strings"
-	"testing"
-
-	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
-)
-
-const testID = id.Zid(98765432101234)
-
-func newMeta(title string, tags []string, syntax string) *meta.Meta {
-	m := meta.New(testID)
-	if title != "" {
-		m.Set(api.KeyTitle, title)
-	}
-	if tags != nil {
-		m.Set(api.KeyTags, strings.Join(tags, " "))
-	}
-	if syntax != "" {
-		m.Set(api.KeySyntax, syntax)
-	}
-	return m
-}
-func assertWriteMeta(t *testing.T, m *meta.Meta, expected string) {
-	t.Helper()
-	var sb strings.Builder
-	m.Write(&sb)
-	if got := sb.String(); got != expected {
-		t.Errorf("\nExp: %q\ngot: %q", expected, got)
-	}
-}
-
-func TestWriteMeta(t *testing.T) {
-	t.Parallel()
-	assertWriteMeta(t, newMeta("", nil, ""), "")
-
-	m := newMeta("TITLE", []string{"#t1", "#t2"}, "syntax")
-	assertWriteMeta(t, m, "title: TITLE\ntags: #t1 #t2\nsyntax: syntax\n")
-
-	m = newMeta("TITLE", nil, "")
-	m.Set("user", "zettel")
-	m.Set("auth", "basic")
-	assertWriteMeta(t, m, "title: TITLE\nauth: basic\nuser: zettel\n")
-}

DELETED domain/zettel.go
Index: domain/zettel.go
==================================================================
--- domain/zettel.go
+++ domain/zettel.go
@@ -1,29 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-// Package domain provides domain specific types, constants, and functions.
-package domain
-
-import "zettelstore.de/z/domain/meta"
-
-// Zettel is the main data object of a zettelstore.
-type Zettel struct {
-	Meta    *meta.Meta // Some additional meta-data.
-	Content Content    // The content of the zettel itself.
-}
-
-// Length returns the number of bytes to store the zettel (in a domain view,
-// not in a technical view).
-func (z Zettel) Length() int { return z.Meta.Length() + z.Content.Length() }
-
-// Equal compares two zettel for equality.
-func (z Zettel) Equal(o Zettel, allowComputed bool) bool {
-	return z.Meta.Equal(o.Meta, allowComputed) && z.Content.Equal(&o.Content)
-}

Index: encoder/encoder.go
==================================================================
--- encoder/encoder.go
+++ encoder/encoder.go
@@ -17,11 +17,11 @@
 	"fmt"
 	"io"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Encoder is an interface that allows to encode different parts of a zettel.
 type Encoder interface {
 	WriteZettel(io.Writer, *ast.ZettelNode, EvalMetaFunc) (int, error)

Index: encoder/encoder_blob_test.go
==================================================================
--- encoder/encoder_blob_test.go
+++ encoder/encoder_blob_test.go
@@ -13,14 +13,14 @@
 import (
 	"testing"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 
 	_ "zettelstore.de/z/parser/blob" // Allow to use BLOB parser.
 )
 
 type blobTestCase struct {
@@ -39,11 +39,11 @@
 			0x06, 0x00, 0x03, 0x36, 0x37, 0x7c, 0xa8, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e, 0x44, 0xae,
 			0x42, 0x60, 0x82,
 		},
 		expect: expectMap{
 			encoderHTML:  `<p><img alt="PNG" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg=="></p>`,
-			encoderSexpr: `(BLOCK (BLOB (INLINE (TEXT "PNG")) "png" "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg=="))`,
+			encoderSz:    `(BLOCK (BLOB (INLINE (TEXT "PNG")) "png" "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg=="))`,
 			encoderSHTML: `((p (img (@ (alt . "PNG") (src . "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABgADNjd8qAAAAABJRU5ErkJggg==")))))`,
 			encoderText:  "",
 			encoderZmk:   `%% Unable to display BLOB with description 'PNG' and syntax 'png'.`,
 		},
 	},

Index: encoder/encoder_block_test.go
==================================================================
--- encoder/encoder_block_test.go
+++ encoder/encoder_block_test.go
@@ -15,11 +15,11 @@
 		descr: "Empty Zettelmarkup should produce near nothing",
 		zmk:   "",
 		expect: expectMap{
 			encoderHTML:  "",
 			encoderMD:    "",
-			encoderSexpr: `(BLOCK)`,
+			encoderSz:    `(BLOCK)`,
 			encoderSHTML: `()`,
 			encoderText:  "",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -27,11 +27,11 @@
 		descr: "Simple text: Hello, world",
 		zmk:   "Hello, world",
 		expect: expectMap{
 			encoderHTML:  "<p>Hello, world</p>",
 			encoderMD:    "Hello, world",
-			encoderSexpr: `(BLOCK (PARA (TEXT "Hello,") (SPACE) (TEXT "world")))`,
+			encoderSz:    `(BLOCK (PARA (TEXT "Hello,") (SPACE) (TEXT "world")))`,
 			encoderSHTML: `((p "Hello," " " "world"))`,
 			encoderText:  "Hello, world",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -39,11 +39,11 @@
 		descr: "Simple block comment",
 		zmk:   "%%%\nNo\nrender\n%%%",
 		expect: expectMap{
 			encoderHTML:  ``,
 			encoderMD:    "",
-			encoderSexpr: `(BLOCK (VERBATIM-COMMENT () "No\nrender"))`,
+			encoderSz:    `(BLOCK (VERBATIM-COMMENT () "No\nrender"))`,
 			encoderSHTML: `(())`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -51,11 +51,11 @@
 		descr: "Rendered block comment",
 		zmk:   "%%%{-}\nRender\n%%%",
 		expect: expectMap{
 			encoderHTML:  "<!--\nRender\n-->\n",
 			encoderMD:    "",
-			encoderSexpr: `(BLOCK (VERBATIM-COMMENT (quote (("-" . ""))) "Render"))`,
+			encoderSz:    `(BLOCK (VERBATIM-COMMENT (quote (("-" . ""))) "Render"))`,
 			encoderSHTML: "((@@@ \"Render\"))",
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -63,11 +63,11 @@
 		descr: "Simple Heading",
 		zmk:   `=== Top`,
 		expect: expectMap{
 			encoderHTML:  "<h2 id=\"top\">Top</h2>",
 			encoderMD:    "# Top",
-			encoderSexpr: `(BLOCK (HEADING 1 () "top" "top" (INLINE (TEXT "Top"))))`,
+			encoderSz:    `(BLOCK (HEADING 1 () "top" "top" (INLINE (TEXT "Top"))))`,
 			encoderSHTML: `((h2 (@ (id . "top")) "Top"))`,
 			encoderText:  `Top`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -75,11 +75,11 @@
 		descr: "Simple List",
 		zmk:   "* A\n* B\n* C",
 		expect: expectMap{
 			encoderHTML:  "<ul><li>A</li><li>B</li><li>C</li></ul>",
 			encoderMD:    "* A\n* B\n* C",
-			encoderSexpr: `(BLOCK (UNORDERED (INLINE (TEXT "A")) (INLINE (TEXT "B")) (INLINE (TEXT "C"))))`,
+			encoderSz:    `(BLOCK (UNORDERED (INLINE (TEXT "A")) (INLINE (TEXT "B")) (INLINE (TEXT "C"))))`,
 			encoderSHTML: `((ul (li "A") (li "B") (li "C")))`,
 			encoderText:  "A\nB\nC",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -87,11 +87,11 @@
 		descr: "Nested List",
 		zmk:   "* T1\n** T2\n* T3\n** T4\n** T5\n* T6",
 		expect: expectMap{
 			encoderHTML:  `<ul><li><p>T1</p><ul><li>T2</li></ul></li><li><p>T3</p><ul><li>T4</li><li>T5</li></ul></li><li><p>T6</p></li></ul>`,
 			encoderMD:    "* T1\n    * T2\n* T3\n    * T4\n    * T5\n* T6",
-			encoderSexpr: `(BLOCK (UNORDERED (BLOCK (PARA (TEXT "T1")) (UNORDERED (INLINE (TEXT "T2")))) (BLOCK (PARA (TEXT "T3")) (UNORDERED (INLINE (TEXT "T4")) (INLINE (TEXT "T5")))) (BLOCK (PARA (TEXT "T6")))))`,
+			encoderSz:    `(BLOCK (UNORDERED (BLOCK (PARA (TEXT "T1")) (UNORDERED (INLINE (TEXT "T2")))) (BLOCK (PARA (TEXT "T3")) (UNORDERED (INLINE (TEXT "T4")) (INLINE (TEXT "T5")))) (BLOCK (PARA (TEXT "T6")))))`,
 			encoderSHTML: `((ul (li (p "T1") (ul (li "T2"))) (li (p "T3") (ul (li "T4") (li "T5"))) (li (p "T6"))))`,
 			encoderText:  "T1\nT2\nT3\nT4\nT5\nT6",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -99,11 +99,11 @@
 		descr: "Sequence of two lists",
 		zmk:   "* Item1.1\n* Item1.2\n* Item1.3\n\n* Item2.1\n* Item2.2",
 		expect: expectMap{
 			encoderHTML:  "<ul><li>Item1.1</li><li>Item1.2</li><li>Item1.3</li><li>Item2.1</li><li>Item2.2</li></ul>",
 			encoderMD:    "* Item1.1\n* Item1.2\n* Item1.3\n* Item2.1\n* Item2.2",
-			encoderSexpr: `(BLOCK (UNORDERED (INLINE (TEXT "Item1.1")) (INLINE (TEXT "Item1.2")) (INLINE (TEXT "Item1.3")) (INLINE (TEXT "Item2.1")) (INLINE (TEXT "Item2.2"))))`,
+			encoderSz:    `(BLOCK (UNORDERED (INLINE (TEXT "Item1.1")) (INLINE (TEXT "Item1.2")) (INLINE (TEXT "Item1.3")) (INLINE (TEXT "Item2.1")) (INLINE (TEXT "Item2.2"))))`,
 			encoderSHTML: `((ul (li "Item1.1") (li "Item1.2") (li "Item1.3") (li "Item2.1") (li "Item2.2")))`,
 			encoderText:  "Item1.1\nItem1.2\nItem1.3\nItem2.1\nItem2.2",
 			encoderZmk:   "* Item1.1\n* Item1.2\n* Item1.3\n* Item2.1\n* Item2.2",
 		},
 	},
@@ -111,11 +111,11 @@
 		descr: "Simple horizontal rule",
 		zmk:   `---`,
 		expect: expectMap{
 			encoderHTML:  "<hr>",
 			encoderMD:    "---",
-			encoderSexpr: `(BLOCK (THEMATIC ()))`,
+			encoderSz:    `(BLOCK (THEMATIC ()))`,
 			encoderSHTML: `((hr))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -123,11 +123,11 @@
 		descr: "Thematic break with attribute",
 		zmk:   `---{lang="zmk"}`,
 		expect: expectMap{
 			encoderHTML:  `<hr lang="zmk">`,
 			encoderMD:    "---",
-			encoderSexpr: `(BLOCK (THEMATIC (quote (("lang" . "zmk")))))`,
+			encoderSz:    `(BLOCK (THEMATIC (quote (("lang" . "zmk")))))`,
 			encoderSHTML: `((hr (@ (lang . "zmk"))))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -135,11 +135,11 @@
 		descr: "No list after paragraph",
 		zmk:   "Text\n*abc",
 		expect: expectMap{
 			encoderHTML:  "<p>Text *abc</p>",
 			encoderMD:    "Text\n*abc",
-			encoderSexpr: `(BLOCK (PARA (TEXT "Text") (SOFT) (TEXT "*abc")))`,
+			encoderSz:    `(BLOCK (PARA (TEXT "Text") (SOFT) (TEXT "*abc")))`,
 			encoderSHTML: `((p "Text" " " "*abc"))`,
 			encoderText:  `Text *abc`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -147,11 +147,11 @@
 		descr: "A list after paragraph",
 		zmk:   "Text\n# abc",
 		expect: expectMap{
 			encoderHTML:  "<p>Text</p><ol><li>abc</li></ol>",
 			encoderMD:    "Text\n\n1. abc",
-			encoderSexpr: `(BLOCK (PARA (TEXT "Text")) (ORDERED (INLINE (TEXT "abc"))))`,
+			encoderSz:    `(BLOCK (PARA (TEXT "Text")) (ORDERED (INLINE (TEXT "abc"))))`,
 			encoderSHTML: `((p "Text") (ol (li "abc")))`,
 			encoderText:  "Text\nabc",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -159,11 +159,11 @@
 		descr: "Simple List Quote",
 		zmk:   "> ToBeOrNotToBe",
 		expect: expectMap{
 			encoderHTML:  "<blockquote><p>ToBeOrNotToBe</p></blockquote>",
 			encoderMD:    "> ToBeOrNotToBe",
-			encoderSexpr: `(BLOCK (QUOTATION (INLINE (TEXT "ToBeOrNotToBe"))))`,
+			encoderSz:    `(BLOCK (QUOTATION (INLINE (TEXT "ToBeOrNotToBe"))))`,
 			encoderSHTML: `((blockquote (p "ToBeOrNotToBe")))`,
 			encoderText:  "ToBeOrNotToBe",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -171,11 +171,11 @@
 		descr: "Simple Quote Block",
 		zmk:   "<<<\nToBeOrNotToBe\n<<< Romeo",
 		expect: expectMap{
 			encoderHTML:  "<blockquote><p>ToBeOrNotToBe</p><cite>Romeo</cite></blockquote>",
 			encoderMD:    "> ToBeOrNotToBe",
-			encoderSexpr: `(BLOCK (REGION-QUOTE () (BLOCK (PARA (TEXT "ToBeOrNotToBe"))) (INLINE (TEXT "Romeo"))))`,
+			encoderSz:    `(BLOCK (REGION-QUOTE () (BLOCK (PARA (TEXT "ToBeOrNotToBe"))) (INLINE (TEXT "Romeo"))))`,
 			encoderSHTML: `((blockquote (p "ToBeOrNotToBe") (cite "Romeo")))`,
 			encoderText:  "ToBeOrNotToBe\nRomeo",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -183,11 +183,11 @@
 		descr: "Quote Block with multiple paragraphs",
 		zmk:   "<<<\nToBeOr\n\nNotToBe\n<<< Romeo",
 		expect: expectMap{
 			encoderHTML:  "<blockquote><p>ToBeOr</p><p>NotToBe</p><cite>Romeo</cite></blockquote>",
 			encoderMD:    "> ToBeOr\n\n> NotToBe",
-			encoderSexpr: `(BLOCK (REGION-QUOTE () (BLOCK (PARA (TEXT "ToBeOr")) (PARA (TEXT "NotToBe"))) (INLINE (TEXT "Romeo"))))`,
+			encoderSz:    `(BLOCK (REGION-QUOTE () (BLOCK (PARA (TEXT "ToBeOr")) (PARA (TEXT "NotToBe"))) (INLINE (TEXT "Romeo"))))`,
 			encoderSHTML: `((blockquote (p "ToBeOr") (p "NotToBe") (cite "Romeo")))`,
 			encoderText:  "ToBeOr\nNotToBe\nRomeo",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -203,11 +203,11 @@
     Spacy  Para
 """ Author`,
 		expect: expectMap{
 			encoderHTML:  "<div><p>A\u00a0line<br>\u00a0\u00a0another\u00a0line<br>Back</p><p>Paragraph</p><p>\u00a0\u00a0\u00a0\u00a0Spacy\u00a0\u00a0Para</p><cite>Author</cite></div>",
 			encoderMD:    "",
-			encoderSexpr: "(BLOCK (REGION-VERSE () (BLOCK (PARA (TEXT \"A\") (SPACE \"\u00a0\") (TEXT \"line\") (HARD) (SPACE \"\u00a0\u00a0\") (TEXT \"another\") (SPACE \"\u00a0\") (TEXT \"line\") (HARD) (TEXT \"Back\")) (PARA (TEXT \"Paragraph\")) (PARA (SPACE \"\u00a0\u00a0\u00a0\u00a0\") (TEXT \"Spacy\") (SPACE \"\u00a0\u00a0\") (TEXT \"Para\"))) (INLINE (TEXT \"Author\"))))",
+			encoderSz:    "(BLOCK (REGION-VERSE () (BLOCK (PARA (TEXT \"A\") (SPACE \"\u00a0\") (TEXT \"line\") (HARD) (SPACE \"\u00a0\u00a0\") (TEXT \"another\") (SPACE \"\u00a0\") (TEXT \"line\") (HARD) (TEXT \"Back\")) (PARA (TEXT \"Paragraph\")) (PARA (SPACE \"\u00a0\u00a0\u00a0\u00a0\") (TEXT \"Spacy\") (SPACE \"\u00a0\u00a0\") (TEXT \"Para\"))) (INLINE (TEXT \"Author\"))))",
 			encoderSHTML: "((div (p \"A\" \"\u00a0\" \"line\" (br) \"\u00a0\u00a0\" \"another\" \"\u00a0\" \"line\" (br) \"Back\") (p \"Paragraph\") (p \"\u00a0\u00a0\u00a0\u00a0\" \"Spacy\" \"\u00a0\u00a0\" \"Para\") (cite \"Author\")))",
 			encoderText:  "A line\n another line\nBack\nParagraph\n Spacy Para\nAuthor",
 			encoderZmk:   "\"\"\"\nA\u00a0line\\\n\u00a0\u00a0another\u00a0line\\\nBack\nParagraph\n\u00a0\u00a0\u00a0\u00a0Spacy\u00a0\u00a0Para\n\"\"\" Author",
 		},
 	},
@@ -219,11 +219,11 @@
 and much more
 :::`,
 		expect: expectMap{
 			encoderHTML:  "<div><p>A simple  span and much more</p></div>",
 			encoderMD:    "",
-			encoderSexpr: `(BLOCK (REGION-BLOCK () (BLOCK (PARA (TEXT "A") (SPACE) (TEXT "simple") (SOFT) (SPACE) (TEXT "span") (SOFT) (TEXT "and") (SPACE) (TEXT "much") (SPACE) (TEXT "more"))) (INLINE)))`,
+			encoderSz:    `(BLOCK (REGION-BLOCK () (BLOCK (PARA (TEXT "A") (SPACE) (TEXT "simple") (SOFT) (SPACE) (TEXT "span") (SOFT) (TEXT "and") (SPACE) (TEXT "much") (SPACE) (TEXT "more"))) (INLINE)))`,
 			encoderSHTML: `((div (p "A" " " "simple" " " " " "span" " " "and" " " "much" " " "more")))`,
 			encoderText:  `A simple  span and much more`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -231,11 +231,11 @@
 		descr: "Simple Verbatim Code",
 		zmk:   "```\nHello\nWorld\n```",
 		expect: expectMap{
 			encoderHTML:  "<pre><code>Hello\nWorld</code></pre>",
 			encoderMD:    "    Hello\n    World",
-			encoderSexpr: `(BLOCK (VERBATIM-CODE () "Hello\nWorld"))`,
+			encoderSz:    `(BLOCK (VERBATIM-CODE () "Hello\nWorld"))`,
 			encoderSHTML: `((pre (code "Hello\nWorld")))`,
 			encoderText:  "Hello\nWorld",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -243,11 +243,11 @@
 		descr: "Simple Verbatim Code with visible spaces",
 		zmk:   "```{-}\nHello World\n```",
 		expect: expectMap{
 			encoderHTML:  "<pre><code>Hello\u2423World</code></pre>",
 			encoderMD:    "    Hello World",
-			encoderSexpr: `(BLOCK (VERBATIM-CODE (quote (("-" . ""))) "Hello World"))`,
+			encoderSz:    `(BLOCK (VERBATIM-CODE (quote (("-" . ""))) "Hello World"))`,
 			encoderSHTML: "((pre (code \"Hello\u2423World\")))",
 			encoderText:  "Hello World",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -255,11 +255,11 @@
 		descr: "Simple Verbatim Eval",
 		zmk:   "~~~\nHello\nWorld\n~~~",
 		expect: expectMap{
 			encoderHTML:  "<pre><code class=\"zs-eval\">Hello\nWorld</code></pre>",
 			encoderMD:    "",
-			encoderSexpr: `(BLOCK (VERBATIM-EVAL () "Hello\nWorld"))`,
+			encoderSz:    `(BLOCK (VERBATIM-EVAL () "Hello\nWorld"))`,
 			encoderSHTML: "((pre (code (@ (class . \"zs-eval\")) \"Hello\\nWorld\")))",
 			encoderText:  "Hello\nWorld",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -267,11 +267,11 @@
 		descr: "Simple Verbatim Math",
 		zmk:   "$$$\nHello\n\\LaTeX\n$$$",
 		expect: expectMap{
 			encoderHTML:  "<pre><code class=\"zs-math\">Hello\n\\LaTeX</code></pre>",
 			encoderMD:    "",
-			encoderSexpr: `(BLOCK (VERBATIM-MATH () "Hello\n\\LaTeX"))`,
+			encoderSz:    `(BLOCK (VERBATIM-MATH () "Hello\n\\LaTeX"))`,
 			encoderSHTML: "((pre (code (@ (class . \"zs-math\")) \"Hello\\n\\\\LaTeX\")))",
 			encoderText:  "Hello\n\\LaTeX",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -279,11 +279,11 @@
 		descr: "Simple Description List",
 		zmk:   "; Zettel\n: Paper\n: Note\n; Zettelkasten\n: Slip box",
 		expect: expectMap{
 			encoderHTML:  "<dl><dt>Zettel</dt><dd><p>Paper</p></dd><dd><p>Note</p></dd><dt>Zettelkasten</dt><dd><p>Slip box</p></dd></dl>",
 			encoderMD:    "",
-			encoderSexpr: `(BLOCK (DESCRIPTION (INLINE (TEXT "Zettel")) (BLOCK (BLOCK (PARA (TEXT "Paper"))) (BLOCK (PARA (TEXT "Note")))) (INLINE (TEXT "Zettelkasten")) (BLOCK (BLOCK (PARA (TEXT "Slip") (SPACE) (TEXT "box"))))))`,
+			encoderSz:    `(BLOCK (DESCRIPTION (INLINE (TEXT "Zettel")) (BLOCK (BLOCK (PARA (TEXT "Paper"))) (BLOCK (PARA (TEXT "Note")))) (INLINE (TEXT "Zettelkasten")) (BLOCK (BLOCK (PARA (TEXT "Slip") (SPACE) (TEXT "box"))))))`,
 			encoderSHTML: `((dl (dt "Zettel") (dd (p "Paper")) (dd (p "Note")) (dt "Zettelkasten") (dd (p "Slip" " " "box"))))`,
 			encoderText:  "Zettel\nPaper\nNote\nZettelkasten\nSlip box",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -291,11 +291,11 @@
 		descr: "Description List with paragraphs as item",
 		zmk:   "; Zettel\n: Paper\n\n  Note\n; Zettelkasten\n: Slip box",
 		expect: expectMap{
 			encoderHTML:  "<dl><dt>Zettel</dt><dd><p>Paper</p><p>Note</p></dd><dt>Zettelkasten</dt><dd><p>Slip box</p></dd></dl>",
 			encoderMD:    "",
-			encoderSexpr: `(BLOCK (DESCRIPTION (INLINE (TEXT "Zettel")) (BLOCK (BLOCK (PARA (TEXT "Paper")) (PARA (TEXT "Note")))) (INLINE (TEXT "Zettelkasten")) (BLOCK (BLOCK (PARA (TEXT "Slip") (SPACE) (TEXT "box"))))))`,
+			encoderSz:    `(BLOCK (DESCRIPTION (INLINE (TEXT "Zettel")) (BLOCK (BLOCK (PARA (TEXT "Paper")) (PARA (TEXT "Note")))) (INLINE (TEXT "Zettelkasten")) (BLOCK (BLOCK (PARA (TEXT "Slip") (SPACE) (TEXT "box"))))))`,
 			encoderSHTML: `((dl (dt "Zettel") (dd (p "Paper") (p "Note")) (dt "Zettelkasten") (dd (p "Slip" " " "box"))))`,
 			encoderText:  "Zettel\nPaper\nNote\nZettelkasten\nSlip box",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -303,11 +303,11 @@
 		descr: "Simple Table",
 		zmk:   "|c1|c2|c3\n|d1||d3",
 		expect: expectMap{
 			encoderHTML:  `<table><tbody><tr><td>c1</td><td>c2</td><td>c3</td></tr><tr><td>d1</td><td></td><td>d3</td></tr></tbody></table>`,
 			encoderMD:    "",
-			encoderSexpr: `(BLOCK (TABLE () (LIST (CELL (TEXT "c1")) (CELL (TEXT "c2")) (CELL (TEXT "c3"))) (LIST (CELL (TEXT "d1")) (CELL) (CELL (TEXT "d3")))))`,
+			encoderSz:    `(BLOCK (TABLE () (list (CELL (TEXT "c1")) (CELL (TEXT "c2")) (CELL (TEXT "c3"))) (list (CELL (TEXT "d1")) (CELL) (CELL (TEXT "d3")))))`,
 			encoderSHTML: `((table (tbody (tr (td "c1") (td "c2") (td "c3")) (tr (td "d1") (td) (td "d3")))))`,
 			encoderText:  "c1 c2 c3\nd1  d3",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -318,11 +318,11 @@
 |<c1|c2|:c3|
 |f1|f2|=f3`,
 		expect: expectMap{
 			encoderHTML:  `<table><thead><tr><td class="right">h1</td><td>h2</td><td class="center">h3</td></tr></thead><tbody><tr><td class="left">c1</td><td>c2</td><td class="center">c3</td></tr><tr><td class="right">f1</td><td>f2</td><td class="center">=f3</td></tr></tbody></table>`,
 			encoderMD:    "",
-			encoderSexpr: `(BLOCK (TABLE (LIST (CELL-RIGHT (TEXT "h1")) (CELL (TEXT "h2")) (CELL-CENTER (TEXT "h3"))) (LIST (CELL-LEFT (TEXT "c1")) (CELL (TEXT "c2")) (CELL-CENTER (TEXT "c3"))) (LIST (CELL-RIGHT (TEXT "f1")) (CELL (TEXT "f2")) (CELL-CENTER (TEXT "=f3")))))`,
+			encoderSz:    `(BLOCK (TABLE (list (CELL-RIGHT (TEXT "h1")) (CELL (TEXT "h2")) (CELL-CENTER (TEXT "h3"))) (list (CELL-LEFT (TEXT "c1")) (CELL (TEXT "c2")) (CELL-CENTER (TEXT "c3"))) (list (CELL-RIGHT (TEXT "f1")) (CELL (TEXT "f2")) (CELL-CENTER (TEXT "=f3")))))`,
 			encoderSHTML: `((table (thead (tr (td (@ (class . "right")) "h1") (td "h2") (td (@ (class . "center")) "h3"))) (tbody (tr (td (@ (class . "left")) "c1") (td "c2") (td (@ (class . "center")) "c3")) (tr (td (@ (class . "right")) "f1") (td "f2") (td (@ (class . "center")) "=f3")))))`,
 			encoderText:  "h1 h2 h3\nc1 c2 c3\nf1 f2 =f3",
 			encoderZmk: `|=h1>|=h2|=h3:
 |<c1|c2|c3
 |f1|f2|=f3`,
@@ -332,11 +332,11 @@
 		descr: "Simple Endnote",
 		zmk:   `Text[^Endnote]`,
 		expect: expectMap{
 			encoderHTML:  "<p>Text<sup id=\"fnref:1\"><a class=\"zs-noteref\" href=\"#fn:1\" role=\"doc-noteref\">1</a></sup></p><ol class=\"zs-endnotes\"><li class=\"zs-endnote\" id=\"fn:1\" role=\"doc-endnote\" value=\"1\">Endnote <a class=\"zs-endnote-backref\" href=\"#fnref:1\" role=\"doc-backlink\">\u21a9\ufe0e</a></li></ol>",
 			encoderMD:    "Text",
-			encoderSexpr: `(BLOCK (PARA (TEXT "Text") (ENDNOTE () (quote (INLINE (TEXT "Endnote"))))))`,
+			encoderSz:    `(BLOCK (PARA (TEXT "Text") (ENDNOTE () (quote (INLINE (TEXT "Endnote"))))))`,
 			encoderSHTML: "((p \"Text\" (sup (@ (id . \"fnref:1\")) (a (@ (class . \"zs-noteref\") (href . \"#fn:1\") (role . \"doc-noteref\")) \"1\"))))",
 			encoderText:  "Text Endnote",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -344,11 +344,11 @@
 		descr: "Nested Endnotes",
 		zmk:   `Text[^Endnote[^Nested]]`,
 		expect: expectMap{
 			encoderHTML:  "<p>Text<sup id=\"fnref:1\"><a class=\"zs-noteref\" href=\"#fn:1\" role=\"doc-noteref\">1</a></sup></p><ol class=\"zs-endnotes\"><li class=\"zs-endnote\" id=\"fn:1\" role=\"doc-endnote\" value=\"1\">Endnote<sup id=\"fnref:2\"><a class=\"zs-noteref\" href=\"#fn:2\" role=\"doc-noteref\">2</a></sup> <a class=\"zs-endnote-backref\" href=\"#fnref:1\" role=\"doc-backlink\">\u21a9\ufe0e</a></li><li class=\"zs-endnote\" id=\"fn:2\" role=\"doc-endnote\" value=\"2\">Nested <a class=\"zs-endnote-backref\" href=\"#fnref:2\" role=\"doc-backlink\">\u21a9\ufe0e</a></li></ol>",
 			encoderMD:    "Text",
-			encoderSexpr: `(BLOCK (PARA (TEXT "Text") (ENDNOTE () (quote (INLINE (TEXT "Endnote") (ENDNOTE () (quote (INLINE (TEXT "Nested")))))))))`,
+			encoderSz:    `(BLOCK (PARA (TEXT "Text") (ENDNOTE () (quote (INLINE (TEXT "Endnote") (ENDNOTE () (quote (INLINE (TEXT "Nested")))))))))`,
 			encoderSHTML: "((p \"Text\" (sup (@ (id . \"fnref:1\")) (a (@ (class . \"zs-noteref\") (href . \"#fn:1\") (role . \"doc-noteref\")) \"1\"))))",
 			encoderText:  "Text Endnote Nested",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -356,11 +356,11 @@
 		descr: "Transclusion",
 		zmk:   `{{{http://example.com/image}}}{width="100px"}`,
 		expect: expectMap{
 			encoderHTML:  `<p><img class="external" src="http://example.com/image" width="100px"></p>`,
 			encoderMD:    "",
-			encoderSexpr: `(BLOCK (TRANSCLUDE (quote (("width" . "100px"))) (quote (EXTERNAL "http://example.com/image"))))`,
+			encoderSz:    `(BLOCK (TRANSCLUDE (quote (("width" . "100px"))) (quote (EXTERNAL "http://example.com/image"))))`,
 			encoderSHTML: `((p (img (@ (class . "external") (src . "http://example.com/image") (width . "100px")))))`,
 			encoderText:  "",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -367,11 +367,11 @@
 	{
 		descr: "A paragraph with a inline comment only should be empty in HTML",
 		zmk:   `%% Comment`,
 		expect: expectMap{
 			// encoderHTML:  ``,
-			encoderSexpr: `(BLOCK (PARA (LITERAL-COMMENT () "Comment")))`,
+			encoderSz: `(BLOCK (PARA (LITERAL-COMMENT () "Comment")))`,
 			// encoderSHTML: ``,
 			encoderText: "",
 			encoderZmk:  useZmk,
 		},
 	},
@@ -378,11 +378,11 @@
 	{
 		descr: "",
 		zmk:   ``,
 		expect: expectMap{
 			encoderHTML:  ``,
-			encoderSexpr: `(BLOCK)`,
+			encoderSz:    `(BLOCK)`,
 			encoderSHTML: `()`,
 			encoderText:  "",
 			encoderZmk:   useZmk,
 		},
 	},

Index: encoder/encoder_inline_test.go
==================================================================
--- encoder/encoder_inline_test.go
+++ encoder/encoder_inline_test.go
@@ -15,11 +15,11 @@
 		descr: "Empty Zettelmarkup should produce near nothing (inline)",
 		zmk:   "",
 		expect: expectMap{
 			encoderHTML:  "",
 			encoderMD:    "",
-			encoderSexpr: `(INLINE)`,
+			encoderSz:    `(INLINE)`,
 			encoderSHTML: `()`,
 			encoderText:  "",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -27,11 +27,11 @@
 		descr: "Simple text: Hello, world (inline)",
 		zmk:   `Hello, world`,
 		expect: expectMap{
 			encoderHTML:  "Hello, world",
 			encoderMD:    "Hello, world",
-			encoderSexpr: `(INLINE (TEXT "Hello,") (SPACE) (TEXT "world"))`,
+			encoderSz:    `(INLINE (TEXT "Hello,") (SPACE) (TEXT "world"))`,
 			encoderSHTML: `("Hello," " " "world")`,
 			encoderText:  "Hello, world",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -39,11 +39,11 @@
 		descr: "Soft Break",
 		zmk:   "soft\nbreak",
 		expect: expectMap{
 			encoderHTML:  "soft break",
 			encoderMD:    "soft\nbreak",
-			encoderSexpr: `(INLINE (TEXT "soft") (SOFT) (TEXT "break"))`,
+			encoderSz:    `(INLINE (TEXT "soft") (SOFT) (TEXT "break"))`,
 			encoderSHTML: `("soft" " " "break")`,
 			encoderText:  "soft break",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -51,11 +51,11 @@
 		descr: "Hard Break",
 		zmk:   "hard\\\nbreak",
 		expect: expectMap{
 			encoderHTML:  "hard<br>break",
 			encoderMD:    "hard\\\nbreak",
-			encoderSexpr: `(INLINE (TEXT "hard") (HARD) (TEXT "break"))`,
+			encoderSz:    `(INLINE (TEXT "hard") (HARD) (TEXT "break"))`,
 			encoderSHTML: `("hard" (br) "break")`,
 			encoderText:  "hard\nbreak",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -63,11 +63,11 @@
 		descr: "Emphasized formatting",
 		zmk:   "__emph__",
 		expect: expectMap{
 			encoderHTML:  "<em>emph</em>",
 			encoderMD:    "*emph*",
-			encoderSexpr: `(INLINE (FORMAT-EMPH () (TEXT "emph")))`,
+			encoderSz:    `(INLINE (FORMAT-EMPH () (TEXT "emph")))`,
 			encoderSHTML: `((em "emph"))`,
 			encoderText:  "emph",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -75,11 +75,11 @@
 		descr: "Strong formatting",
 		zmk:   "**strong**",
 		expect: expectMap{
 			encoderHTML:  "<strong>strong</strong>",
 			encoderMD:    "__strong__",
-			encoderSexpr: `(INLINE (FORMAT-STRONG () (TEXT "strong")))`,
+			encoderSz:    `(INLINE (FORMAT-STRONG () (TEXT "strong")))`,
 			encoderSHTML: `((strong "strong"))`,
 			encoderText:  "strong",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -87,11 +87,11 @@
 		descr: "Insert formatting",
 		zmk:   ">>insert>>",
 		expect: expectMap{
 			encoderHTML:  "<ins>insert</ins>",
 			encoderMD:    "insert",
-			encoderSexpr: `(INLINE (FORMAT-INSERT () (TEXT "insert")))`,
+			encoderSz:    `(INLINE (FORMAT-INSERT () (TEXT "insert")))`,
 			encoderSHTML: `((ins "insert"))`,
 			encoderText:  "insert",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -99,11 +99,11 @@
 		descr: "Delete formatting",
 		zmk:   "~~delete~~",
 		expect: expectMap{
 			encoderHTML:  "<del>delete</del>",
 			encoderMD:    "delete",
-			encoderSexpr: `(INLINE (FORMAT-DELETE () (TEXT "delete")))`,
+			encoderSz:    `(INLINE (FORMAT-DELETE () (TEXT "delete")))`,
 			encoderSHTML: `((del "delete"))`,
 			encoderText:  "delete",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -111,11 +111,11 @@
 		descr: "Update formatting",
 		zmk:   "~~old~~>>new>>",
 		expect: expectMap{
 			encoderHTML:  "<del>old</del><ins>new</ins>",
 			encoderMD:    "oldnew",
-			encoderSexpr: `(INLINE (FORMAT-DELETE () (TEXT "old")) (FORMAT-INSERT () (TEXT "new")))`,
+			encoderSz:    `(INLINE (FORMAT-DELETE () (TEXT "old")) (FORMAT-INSERT () (TEXT "new")))`,
 			encoderSHTML: `((del "old") (ins "new"))`,
 			encoderText:  "oldnew",
 			encoderZmk:   useZmk,
 		},
 	},
@@ -123,11 +123,11 @@
 		descr: "Superscript formatting",
 		zmk:   "^^superscript^^",
 		expect: expectMap{
 			encoderHTML:  `<sup>superscript</sup>`,
 			encoderMD:    "superscript",
-			encoderSexpr: `(INLINE (FORMAT-SUPER () (TEXT "superscript")))`,
+			encoderSz:    `(INLINE (FORMAT-SUPER () (TEXT "superscript")))`,
 			encoderSHTML: `((sup "superscript"))`,
 			encoderText:  `superscript`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -135,11 +135,11 @@
 		descr: "Subscript formatting",
 		zmk:   ",,subscript,,",
 		expect: expectMap{
 			encoderHTML:  `<sub>subscript</sub>`,
 			encoderMD:    "subscript",
-			encoderSexpr: `(INLINE (FORMAT-SUB () (TEXT "subscript")))`,
+			encoderSz:    `(INLINE (FORMAT-SUB () (TEXT "subscript")))`,
 			encoderSHTML: `((sub "subscript"))`,
 			encoderText:  `subscript`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -147,11 +147,11 @@
 		descr: "Quotes formatting",
 		zmk:   `""quotes""`,
 		expect: expectMap{
 			encoderHTML:  "<q>quotes</q>",
 			encoderMD:    "<q>quotes</q>",
-			encoderSexpr: `(INLINE (FORMAT-QUOTE () (TEXT "quotes")))`,
+			encoderSz:    `(INLINE (FORMAT-QUOTE () (TEXT "quotes")))`,
 			encoderSHTML: `((q "quotes"))`,
 			encoderText:  `quotes`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -159,11 +159,11 @@
 		descr: "Quotes formatting (german)",
 		zmk:   `""quotes""{lang=de}`,
 		expect: expectMap{
 			encoderHTML:  `<span lang="de"><q>quotes</q></span>`,
 			encoderMD:    "<q>quotes</q>",
-			encoderSexpr: `(INLINE (FORMAT-QUOTE (quote (("lang" . "de"))) (TEXT "quotes")))`,
+			encoderSz:    `(INLINE (FORMAT-QUOTE (quote (("lang" . "de"))) (TEXT "quotes")))`,
 			encoderSHTML: `((span (@ (lang . "de")) (q "quotes")))`,
 			encoderText:  `quotes`,
 			encoderZmk:   `""quotes""{lang="de"}`,
 		},
 	},
@@ -171,11 +171,11 @@
 		descr: "Span formatting",
 		zmk:   `::span::`,
 		expect: expectMap{
 			encoderHTML:  `<span>span</span>`,
 			encoderMD:    "span",
-			encoderSexpr: `(INLINE (FORMAT-SPAN () (TEXT "span")))`,
+			encoderSz:    `(INLINE (FORMAT-SPAN () (TEXT "span")))`,
 			encoderSHTML: `((span "span"))`,
 			encoderText:  `span`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -183,11 +183,11 @@
 		descr: "Code formatting",
 		zmk:   "``code``",
 		expect: expectMap{
 			encoderHTML:  `<code>code</code>`,
 			encoderMD:    "`code`",
-			encoderSexpr: `(INLINE (LITERAL-CODE () "code"))`,
+			encoderSz:    `(INLINE (LITERAL-CODE () "code"))`,
 			encoderSHTML: `((code "code"))`,
 			encoderText:  `code`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -195,11 +195,11 @@
 		descr: "Code formatting with visible space",
 		zmk:   "``x y``{-}",
 		expect: expectMap{
 			encoderHTML:  "<code>x\u2423y</code>",
 			encoderMD:    "`x y`",
-			encoderSexpr: `(INLINE (LITERAL-CODE (quote (("-" . ""))) "x y"))`,
+			encoderSz:    `(INLINE (LITERAL-CODE (quote (("-" . ""))) "x y"))`,
 			encoderSHTML: "((code \"x\u2423y\"))",
 			encoderText:  `x y`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -207,11 +207,11 @@
 		descr: "HTML in Code formatting",
 		zmk:   "``<script `` abc",
 		expect: expectMap{
 			encoderHTML:  "<code>&lt;script </code> abc",
 			encoderMD:    "`<script ` abc",
-			encoderSexpr: `(INLINE (LITERAL-CODE () "<script ") (SPACE) (TEXT "abc"))`,
+			encoderSz:    `(INLINE (LITERAL-CODE () "<script ") (SPACE) (TEXT "abc"))`,
 			encoderSHTML: `((code "<script ") " " "abc")`,
 			encoderText:  `<script  abc`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -219,11 +219,11 @@
 		descr: "Input formatting",
 		zmk:   `''input''`,
 		expect: expectMap{
 			encoderHTML:  `<kbd>input</kbd>`,
 			encoderMD:    "input",
-			encoderSexpr: `(INLINE (LITERAL-INPUT () "input"))`,
+			encoderSz:    `(INLINE (LITERAL-INPUT () "input"))`,
 			encoderSHTML: `((kbd "input"))`,
 			encoderText:  `input`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -231,11 +231,11 @@
 		descr: "Output formatting",
 		zmk:   `==output==`,
 		expect: expectMap{
 			encoderHTML:  `<samp>output</samp>`,
 			encoderMD:    "output",
-			encoderSexpr: `(INLINE (LITERAL-OUTPUT () "output"))`,
+			encoderSz:    `(INLINE (LITERAL-OUTPUT () "output"))`,
 			encoderSHTML: `((samp "output"))`,
 			encoderText:  `output`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -243,11 +243,11 @@
 		descr: "Math formatting",
 		zmk:   `$$\TeX$$`,
 		expect: expectMap{
 			encoderHTML:  `<code class="zs-math">\TeX</code>`,
 			encoderMD:    "\\TeX",
-			encoderSexpr: `(INLINE (LITERAL-MATH () "\\TeX"))`,
+			encoderSz:    `(INLINE (LITERAL-MATH () "\\TeX"))`,
 			encoderSHTML: `((code (@ (class . "zs-math")) "\\TeX"))`,
 			encoderText:  `\TeX`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -255,11 +255,11 @@
 		descr: "Nested Span Quote formatting",
 		zmk:   `::""abc""::{lang=fr}`,
 		expect: expectMap{
 			encoderHTML:  `<span lang="fr"><q>abc</q></span>`,
 			encoderMD:    "<q>abc</q>",
-			encoderSexpr: `(INLINE (FORMAT-SPAN (quote (("lang" . "fr"))) (FORMAT-QUOTE () (TEXT "abc"))))`,
+			encoderSz:    `(INLINE (FORMAT-SPAN (quote (("lang" . "fr"))) (FORMAT-QUOTE () (TEXT "abc"))))`,
 			encoderSHTML: `((span (@ (lang . "fr")) (q "abc")))`,
 			encoderText:  `abc`,
 			encoderZmk:   `::""abc""::{lang="fr"}`,
 		},
 	},
@@ -267,11 +267,11 @@
 		descr: "Simple Citation",
 		zmk:   `[@Stern18]`,
 		expect: expectMap{
 			encoderHTML:  `<span>Stern18</span>`, // TODO
 			encoderMD:    "",
-			encoderSexpr: `(INLINE (CITE () "Stern18"))`,
+			encoderSz:    `(INLINE (CITE () "Stern18"))`,
 			encoderSHTML: `((span "Stern18"))`, // TODO
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -279,11 +279,11 @@
 		descr: "Citation",
 		zmk:   `[@Stern18 p.23]`,
 		expect: expectMap{
 			encoderHTML:  `<span>Stern18, p.23</span>`, // TODO
 			encoderMD:    "p.23",
-			encoderSexpr: `(INLINE (CITE () "Stern18" (TEXT "p.23")))`,
+			encoderSz:    `(INLINE (CITE () "Stern18" (TEXT "p.23")))`,
 			encoderSHTML: `((span "Stern18" ", " "p.23"))`, // TODO
 			encoderText:  `p.23`,
 			encoderZmk:   useZmk,
 		},
 	}, {
@@ -290,11 +290,11 @@
 		descr: "No comment",
 		zmk:   `% comment`,
 		expect: expectMap{
 			encoderHTML:  `% comment`,
 			encoderMD:    "% comment",
-			encoderSexpr: `(INLINE (TEXT "%") (SPACE) (TEXT "comment"))`,
+			encoderSz:    `(INLINE (TEXT "%") (SPACE) (TEXT "comment"))`,
 			encoderSHTML: `("%" " " "comment")`,
 			encoderText:  `% comment`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -302,11 +302,11 @@
 		descr: "Line comment (nogen HTML)",
 		zmk:   `%% line comment`,
 		expect: expectMap{
 			encoderHTML:  ``,
 			encoderMD:    "",
-			encoderSexpr: `(INLINE (LITERAL-COMMENT () "line comment"))`,
+			encoderSz:    `(INLINE (LITERAL-COMMENT () "line comment"))`,
 			encoderSHTML: `(())`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -314,11 +314,11 @@
 		descr: "Line comment",
 		zmk:   `%%{-} line comment`,
 		expect: expectMap{
 			encoderHTML:  `<!-- line comment -->`,
 			encoderMD:    "",
-			encoderSexpr: `(INLINE (LITERAL-COMMENT (quote (("-" . ""))) "line comment"))`,
+			encoderSz:    `(INLINE (LITERAL-COMMENT (quote (("-" . ""))) "line comment"))`,
 			encoderSHTML: `((@@ "line comment"))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -326,11 +326,11 @@
 		descr: "Comment after text",
 		zmk:   `Text %%{-} comment`,
 		expect: expectMap{
 			encoderHTML:  `Text<!-- comment -->`,
 			encoderMD:    "Text",
-			encoderSexpr: `(INLINE (TEXT "Text") (LITERAL-COMMENT (quote (("-" . ""))) "comment"))`,
+			encoderSz:    `(INLINE (TEXT "Text") (LITERAL-COMMENT (quote (("-" . ""))) "comment"))`,
 			encoderSHTML: `("Text" (@@ "comment"))`,
 			encoderText:  `Text`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -338,11 +338,11 @@
 		descr: "Comment after text and with -->",
 		zmk:   `Text %%{-} comment --> end`,
 		expect: expectMap{
 			encoderHTML:  `Text<!-- comment -&#45;> end -->`,
 			encoderMD:    "Text",
-			encoderSexpr: `(INLINE (TEXT "Text") (LITERAL-COMMENT (quote (("-" . ""))) "comment --> end"))`,
+			encoderSz:    `(INLINE (TEXT "Text") (LITERAL-COMMENT (quote (("-" . ""))) "comment --> end"))`,
 			encoderSHTML: `("Text" (@@ "comment --> end"))`,
 			encoderText:  `Text`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -350,11 +350,11 @@
 		descr: "Simple inline endnote",
 		zmk:   `[^endnote]`,
 		expect: expectMap{
 			encoderHTML:  `<sup id="fnref:1"><a class="zs-noteref" href="#fn:1" role="doc-noteref">1</a></sup>`,
 			encoderMD:    "",
-			encoderSexpr: `(INLINE (ENDNOTE () (quote (INLINE (TEXT "endnote")))))`,
+			encoderSz:    `(INLINE (ENDNOTE () (quote (INLINE (TEXT "endnote")))))`,
 			encoderSHTML: `((sup (@ (id . "fnref:1")) (a (@ (class . "zs-noteref") (href . "#fn:1") (role . "doc-noteref")) "1")))`,
 			encoderText:  `endnote`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -362,11 +362,11 @@
 		descr: "Simple mark",
 		zmk:   `[!mark]`,
 		expect: expectMap{
 			encoderHTML:  `<a id="mark"></a>`,
 			encoderMD:    "",
-			encoderSexpr: `(INLINE (MARK "mark" "mark" "mark"))`,
+			encoderSz:    `(INLINE (MARK "mark" "mark" "mark"))`,
 			encoderSHTML: `((a (@ (id . "mark"))))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -374,11 +374,11 @@
 		descr: "Mark with text",
 		zmk:   `[!mark|with text]`,
 		expect: expectMap{
 			encoderHTML:  `<a id="mark">with text</a>`,
 			encoderMD:    "with text",
-			encoderSexpr: `(INLINE (MARK "mark" "mark" "mark" (TEXT "with") (SPACE) (TEXT "text")))`,
+			encoderSz:    `(INLINE (MARK "mark" "mark" "mark" (TEXT "with") (SPACE) (TEXT "text")))`,
 			encoderSHTML: `((a (@ (id . "mark")) "with" " " "text"))`,
 			encoderText:  `with text`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -386,11 +386,11 @@
 		descr: "Invalid Link",
 		zmk:   `[[link|00000000000000]]`,
 		expect: expectMap{
 			encoderHTML:  `<span>link</span>`,
 			encoderMD:    "[link](00000000000000)",
-			encoderSexpr: `(INLINE (LINK-INVALID () "00000000000000" (TEXT "link")))`,
+			encoderSz:    `(INLINE (LINK-INVALID () "00000000000000" (TEXT "link")))`,
 			encoderSHTML: `((span "link"))`,
 			encoderText:  `link`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -398,11 +398,11 @@
 		descr: "Invalid Simple Link",
 		zmk:   `[[00000000000000]]`,
 		expect: expectMap{
 			encoderHTML:  `<span>00000000000000</span>`,
 			encoderMD:    "[00000000000000](00000000000000)",
-			encoderSexpr: `(INLINE (LINK-INVALID () "00000000000000"))`,
+			encoderSz:    `(INLINE (LINK-INVALID () "00000000000000"))`,
 			encoderSHTML: `((span "00000000000000"))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -410,11 +410,11 @@
 		descr: "Dummy Link",
 		zmk:   `[[abc]]`,
 		expect: expectMap{
 			encoderHTML:  `<a class="external" href="abc">abc</a>`,
 			encoderMD:    "[abc](abc)",
-			encoderSexpr: `(INLINE (LINK-EXTERNAL () "abc"))`,
+			encoderSz:    `(INLINE (LINK-EXTERNAL () "abc"))`,
 			encoderSHTML: `((a (@ (class . "external") (href . "abc")) "abc"))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -422,11 +422,11 @@
 		descr: "Simple URL",
 		zmk:   `[[https://zettelstore.de]]`,
 		expect: expectMap{
 			encoderHTML:  `<a class="external" href="https://zettelstore.de">https://zettelstore.de</a>`,
 			encoderMD:    "<https://zettelstore.de>",
-			encoderSexpr: `(INLINE (LINK-EXTERNAL () "https://zettelstore.de"))`,
+			encoderSz:    `(INLINE (LINK-EXTERNAL () "https://zettelstore.de"))`,
 			encoderSHTML: `((a (@ (class . "external") (href . "https://zettelstore.de")) "https://zettelstore.de"))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -434,11 +434,11 @@
 		descr: "URL with Text",
 		zmk:   `[[Home|https://zettelstore.de]]`,
 		expect: expectMap{
 			encoderHTML:  `<a class="external" href="https://zettelstore.de">Home</a>`,
 			encoderMD:    "[Home](https://zettelstore.de)",
-			encoderSexpr: `(INLINE (LINK-EXTERNAL () "https://zettelstore.de" (TEXT "Home")))`,
+			encoderSz:    `(INLINE (LINK-EXTERNAL () "https://zettelstore.de" (TEXT "Home")))`,
 			encoderSHTML: `((a (@ (class . "external") (href . "https://zettelstore.de")) "Home"))`,
 			encoderText:  `Home`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -446,11 +446,11 @@
 		descr: "Simple Zettel ID",
 		zmk:   `[[00000000000100]]`,
 		expect: expectMap{
 			encoderHTML:  `<a href="00000000000100">00000000000100</a>`,
 			encoderMD:    "[00000000000100](00000000000100)",
-			encoderSexpr: `(INLINE (LINK-ZETTEL () "00000000000100"))`,
+			encoderSz:    `(INLINE (LINK-ZETTEL () "00000000000100"))`,
 			encoderSHTML: `((a (@ (href . "00000000000100")) "00000000000100"))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -458,11 +458,11 @@
 		descr: "Zettel ID with Text",
 		zmk:   `[[Config|00000000000100]]`,
 		expect: expectMap{
 			encoderHTML:  `<a href="00000000000100">Config</a>`,
 			encoderMD:    "[Config](00000000000100)",
-			encoderSexpr: `(INLINE (LINK-ZETTEL () "00000000000100" (TEXT "Config")))`,
+			encoderSz:    `(INLINE (LINK-ZETTEL () "00000000000100" (TEXT "Config")))`,
 			encoderSHTML: `((a (@ (href . "00000000000100")) "Config"))`,
 			encoderText:  `Config`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -470,11 +470,11 @@
 		descr: "Simple Zettel ID with fragment",
 		zmk:   `[[00000000000100#frag]]`,
 		expect: expectMap{
 			encoderHTML:  `<a href="00000000000100#frag">00000000000100#frag</a>`,
 			encoderMD:    "[00000000000100#frag](00000000000100#frag)",
-			encoderSexpr: `(INLINE (LINK-ZETTEL () "00000000000100#frag"))`,
+			encoderSz:    `(INLINE (LINK-ZETTEL () "00000000000100#frag"))`,
 			encoderSHTML: `((a (@ (href . "00000000000100#frag")) "00000000000100#frag"))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -482,11 +482,11 @@
 		descr: "Zettel ID with Text and fragment",
 		zmk:   `[[Config|00000000000100#frag]]`,
 		expect: expectMap{
 			encoderHTML:  `<a href="00000000000100#frag">Config</a>`,
 			encoderMD:    "[Config](00000000000100#frag)",
-			encoderSexpr: `(INLINE (LINK-ZETTEL () "00000000000100#frag" (TEXT "Config")))`,
+			encoderSz:    `(INLINE (LINK-ZETTEL () "00000000000100#frag" (TEXT "Config")))`,
 			encoderSHTML: `((a (@ (href . "00000000000100#frag")) "Config"))`,
 			encoderText:  `Config`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -494,11 +494,11 @@
 		descr: "Fragment link to self",
 		zmk:   `[[#frag]]`,
 		expect: expectMap{
 			encoderHTML:  `<a href="#frag">#frag</a>`,
 			encoderMD:    "[#frag](#frag)",
-			encoderSexpr: `(INLINE (LINK-SELF () "#frag"))`,
+			encoderSz:    `(INLINE (LINK-SELF () "#frag"))`,
 			encoderSHTML: `((a (@ (href . "#frag")) "#frag"))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -506,11 +506,11 @@
 		descr: "Hosted link",
 		zmk:   `[[H|/hosted]]`,
 		expect: expectMap{
 			encoderHTML:  `<a href="/hosted">H</a>`,
 			encoderMD:    "[H](/hosted)",
-			encoderSexpr: `(INLINE (LINK-HOSTED () "/hosted" (TEXT "H")))`,
+			encoderSz:    `(INLINE (LINK-HOSTED () "/hosted" (TEXT "H")))`,
 			encoderSHTML: `((a (@ (href . "/hosted")) "H"))`,
 			encoderText:  `H`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -518,11 +518,11 @@
 		descr: "Based link",
 		zmk:   `[[B|//based]]`,
 		expect: expectMap{
 			encoderHTML:  `<a href="/based">B</a>`,
 			encoderMD:    "[B](/based)",
-			encoderSexpr: `(INLINE (LINK-BASED () "/based" (TEXT "B")))`,
+			encoderSz:    `(INLINE (LINK-BASED () "/based" (TEXT "B")))`,
 			encoderText:  `B`,
 			encoderSHTML: `((a (@ (href . "/based")) "B"))`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -530,11 +530,11 @@
 		descr: "Relative link",
 		zmk:   `[[R|../relative]]`,
 		expect: expectMap{
 			encoderHTML:  `<a href="../relative">R</a>`,
 			encoderMD:    "[R](../relative)",
-			encoderSexpr: `(INLINE (LINK-HOSTED () "../relative" (TEXT "R")))`,
+			encoderSz:    `(INLINE (LINK-HOSTED () "../relative" (TEXT "R")))`,
 			encoderSHTML: `((a (@ (href . "../relative")) "R"))`,
 			encoderText:  `R`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -542,11 +542,11 @@
 		descr: "Query link w/o text",
 		zmk:   `[[query:title:syntax]]`,
 		expect: expectMap{
 			encoderHTML:  `<a href="?q=title%3Asyntax">title:syntax</a>`,
 			encoderMD:    "",
-			encoderSexpr: `(INLINE (LINK-QUERY () "title:syntax"))`,
+			encoderSz:    `(INLINE (LINK-QUERY () "title:syntax"))`,
 			encoderSHTML: `((a (@ (href . "?q=title%3Asyntax")) "title:syntax"))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -554,11 +554,11 @@
 		descr: "Query link with text",
 		zmk:   `[[Q|query:title:syntax]]`,
 		expect: expectMap{
 			encoderHTML:  `<a href="?q=title%3Asyntax">Q</a>`,
 			encoderMD:    "Q",
-			encoderSexpr: `(INLINE (LINK-QUERY () "title:syntax" (TEXT "Q")))`,
+			encoderSz:    `(INLINE (LINK-QUERY () "title:syntax" (TEXT "Q")))`,
 			encoderSHTML: `((a (@ (href . "?q=title%3Asyntax")) "Q"))`,
 			encoderText:  `Q`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -566,11 +566,11 @@
 		descr: "Dummy Embed",
 		zmk:   `{{abc}}`,
 		expect: expectMap{
 			encoderHTML:  `<img src="abc">`,
 			encoderMD:    "![abc](abc)",
-			encoderSexpr: `(INLINE (EMBED () (quote (EXTERNAL "abc")) ""))`,
+			encoderSz:    `(INLINE (EMBED () (quote (EXTERNAL "abc")) ""))`,
 			encoderSHTML: `((img (@ (src . "abc"))))`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -578,11 +578,11 @@
 		descr: "Inline HTML Zettel",
 		zmk:   `@@<hr>@@{="html"}`,
 		expect: expectMap{
 			encoderHTML:  ``,
 			encoderMD:    "",
-			encoderSexpr: `(INLINE)`,
+			encoderSz:    `(INLINE)`,
 			encoderSHTML: `()`,
 			encoderText:  ``,
 			encoderZmk:   ``,
 		},
 	},
@@ -590,11 +590,11 @@
 		descr: "Inline Text Zettel",
 		zmk:   `@@<hr>@@{="text"}`,
 		expect: expectMap{
 			encoderHTML:  ``,
 			encoderMD:    "<hr>",
-			encoderSexpr: `(INLINE (LITERAL-ZETTEL (quote (("" . "text"))) "<hr>"))`,
+			encoderSz:    `(INLINE (LITERAL-ZETTEL (quote (("" . "text"))) "<hr>"))`,
 			encoderSHTML: `(())`,
 			encoderText:  `<hr>`,
 			encoderZmk:   useZmk,
 		},
 	},
@@ -602,12 +602,12 @@
 		descr: "",
 		zmk:   ``,
 		expect: expectMap{
 			encoderHTML:  ``,
 			encoderMD:    "",
-			encoderSexpr: `(INLINE)`,
+			encoderSz:    `(INLINE)`,
 			encoderSHTML: `()`,
 			encoderText:  ``,
 			encoderZmk:   useZmk,
 		},
 	},
 }

Index: encoder/encoder_test.go
==================================================================
--- encoder/encoder_test.go
+++ encoder/encoder_test.go
@@ -17,19 +17,19 @@
 
 	"codeberg.org/t73fde/sxpf/reader"
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 
 	_ "zettelstore.de/z/encoder/htmlenc"  // Allow to use HTML encoder.
 	_ "zettelstore.de/z/encoder/mdenc"    // Allow to use markdown encoder.
-	_ "zettelstore.de/z/encoder/sexprenc" // Allow to use sexpr encoder.
 	_ "zettelstore.de/z/encoder/shtmlenc" // Allow to use SHTML encoder.
+	_ "zettelstore.de/z/encoder/szenc"    // Allow to use sz encoder.
 	_ "zettelstore.de/z/encoder/textenc"  // Allow to use text encoder.
 	_ "zettelstore.de/z/encoder/zmkenc"   // Allow to use zmk encoder.
 	"zettelstore.de/z/parser/cleaner"
 	_ "zettelstore.de/z/parser/zettelmark" // Allow to use zettelmark parser.
 )
@@ -45,11 +45,11 @@
 
 const useZmk = "\000"
 const (
 	encoderHTML  = api.EncoderHTML
 	encoderMD    = api.EncoderMD
-	encoderSexpr = api.EncoderSexpr
+	encoderSz    = api.EncoderSz
 	encoderSHTML = api.EncoderSHTML
 	encoderText  = api.EncoderText
 	encoderZmk   = api.EncoderZmk
 )
 
@@ -70,11 +70,11 @@
 			pe = &peInlines{is: is}
 		} else {
 			pe = &peBlocks{bs: parser.ParseBlocks(inp, nil, meta.SyntaxZmk, config.NoHTML)}
 		}
 		checkEncodings(t, testNum, pe, tc.descr, tc.expect, tc.zmk)
-		checkSexpr(t, testNum, pe, tc.descr)
+		checkSz(t, testNum, pe, tc.descr)
 	}
 }
 
 func checkEncodings(t *testing.T, testNum int, pe parserEncoder, descr string, expected expectMap, zmkDefault string) {
 	for enc, exp := range expected {
@@ -101,13 +101,13 @@
 			t.Errorf("%s\nEncoder:  %s\nExpected: %q\nGot:      %q", prefix, enc, exp, got)
 		}
 	}
 }
 
-func checkSexpr(t *testing.T, testNum int, pe parserEncoder, descr string) {
+func checkSz(t *testing.T, testNum int, pe parserEncoder, descr string) {
 	t.Helper()
-	encdr := encoder.Create(encoderSexpr)
+	encdr := encoder.Create(encoderSz)
 	exp, err := pe.encode(encdr)
 	if err != nil {
 		t.Error(err)
 		return
 	}

Index: encoder/htmlenc/htmlenc.go
==================================================================
--- encoder/htmlenc/htmlenc.go
+++ encoder/htmlenc/htmlenc.go
@@ -18,67 +18,68 @@
 	"codeberg.org/t73fde/sxhtml"
 	"codeberg.org/t73fde/sxpf"
 	"zettelstore.de/c/api"
 	"zettelstore.de/c/shtml"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder"
-	"zettelstore.de/z/encoder/sexprenc"
-	"zettelstore.de/z/encoder/shtmlenc"
+	"zettelstore.de/z/encoder/szenc"
 	"zettelstore.de/z/encoder/textenc"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	encoder.Register(api.EncoderHTML, func() encoder.Encoder { return Create() })
 }
 
 // Create an encoder.
-func Create() *Encoder { return &mySHE }
+func Create() *Encoder {
+	// We need a new transformer every time, because tx.inVerse must be unique.
+	// If we can refactor it out, the transformer can be created only once.
+	return &Encoder{
+		tx:      szenc.NewTransformer(),
+		th:      shtml.NewTransformer(1, nil),
+		textEnc: textenc.Create(),
+	}
+}
 
 type Encoder struct {
+	tx      *szenc.Transformer
+	th      *shtml.Transformer
 	textEnc *textenc.Encoder
 }
 
-var mySHE = Encoder{
-	textEnc: textenc.Create(),
-}
-
 // WriteZettel encodes a full zettel as HTML5.
 func (he *Encoder) WriteZettel(w io.Writer, zn *ast.ZettelNode, evalMeta encoder.EvalMetaFunc) (int, error) {
-	tx := sexprenc.NewTransformer()
-	xm := tx.GetMeta(zn.InhMeta, evalMeta)
-
-	th := shtml.NewTransformer(1, nil)
-	hm, err := th.Transform(xm)
+	hm, err := he.th.Transform(he.tx.GetMeta(zn.InhMeta, evalMeta))
 	if err != nil {
 		return 0, err
 	}
 
 	var isTitle ast.InlineSlice
 	var htitle *sxpf.List
 	plainTitle, hasTitle := zn.InhMeta.Get(api.KeyTitle)
 	if hasTitle {
 		isTitle = parser.ParseSpacedText(plainTitle)
-		xtitle := tx.GetSexpr(&isTitle)
-		htitle, err = th.Transform(xtitle)
+		xtitle := he.tx.GetSz(&isTitle)
+		htitle, err = he.th.Transform(xtitle)
 		if err != nil {
 			return 0, err
 		}
 	}
 
-	xast := tx.GetSexpr(&zn.Ast)
-	hast, err := th.Transform(xast)
+	xast := he.tx.GetSz(&zn.Ast)
+	hast, err := he.th.Transform(xast)
 	if err != nil {
 		return 0, err
 	}
-	hen := th.Endnotes()
+	hen := he.th.Endnotes()
 
-	sf := th.SymbolFactory()
+	sf := he.th.SymbolFactory()
 	symAttr := sf.MustMake(sxhtml.NameSymAttr)
 
-	head := sxpf.Nil().Cons(sf.MustMake("head"))
+	head := sxpf.MakeList(sf.MustMake("head"))
 	curr := head
 	curr = curr.AppendBang(sxpf.Nil().Cons(sxpf.Nil().Cons(sxpf.Cons(sf.MustMake("charset"), sxpf.MakeString("utf-8"))).Cons(symAttr)).Cons(sf.MustMake("meta")))
 	for elem := hm; elem != nil; elem = elem.Tail() {
 		curr = curr.AppendBang(elem.Car())
 	}
@@ -86,11 +87,11 @@
 		var sb strings.Builder
 		he.textEnc.WriteInlines(&sb, &isTitle)
 		_ = curr.AppendBang(sxpf.Nil().Cons(sxpf.MakeString(sb.String())).Cons(sf.MustMake("title")))
 	}
 
-	body := sxpf.Nil().Cons(sf.MustMake("body"))
+	body := sxpf.MakeList(sf.MustMake("body"))
 	curr = body
 	if hasTitle {
 		curr = curr.AppendBang(htitle.Cons(sf.MustMake("h1")))
 	}
 	for elem := hast; elem != nil; elem = elem.Tail() {
@@ -110,50 +111,42 @@
 	return gen.WriteHTML(w, doc)
 }
 
 // WriteMeta encodes meta data as HTML5.
 func (he *Encoder) WriteMeta(w io.Writer, m *meta.Meta, evalMeta encoder.EvalMetaFunc) (int, error) {
-	tx := sexprenc.NewTransformer()
-	xm := tx.GetMeta(m, evalMeta)
-
-	th := shtml.NewTransformer(1, nil)
-	hm, err := th.Transform(xm)
+	hm, err := he.th.Transform(he.tx.GetMeta(m, evalMeta))
 	if err != nil {
 		return 0, err
 	}
-	gen := sxhtml.NewGenerator(th.SymbolFactory(), sxhtml.WithNewline)
+	gen := sxhtml.NewGenerator(he.th.SymbolFactory(), sxhtml.WithNewline)
 	return gen.WriteListHTML(w, hm)
 }
 
 func (he *Encoder) WriteContent(w io.Writer, zn *ast.ZettelNode) (int, error) {
 	return he.WriteBlocks(w, &zn.Ast)
 }
 
 // WriteBlocks encodes a block slice.
-func (*Encoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
-	tx := sexprenc.NewTransformer()
-	xval := tx.GetSexpr(bs)
-	th := shtml.NewTransformer(1, nil)
-	hobj, err := th.Transform(xval)
-
+func (he *Encoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
+	hobj, err := he.th.Transform(he.tx.GetSz(bs))
 	if err == nil {
-		gen := sxhtml.NewGenerator(th.SymbolFactory())
+		gen := sxhtml.NewGenerator(he.th.SymbolFactory())
 		length, err2 := gen.WriteListHTML(w, hobj)
 		if err2 != nil {
 			return length, err2
 		}
 
-		l, err2 := gen.WriteHTML(w, th.Endnotes())
+		l, err2 := gen.WriteHTML(w, he.th.Endnotes())
 		length += l
 		return length, err2
 	}
 	return 0, err
 }
 
 // WriteInlines writes an inline slice to the writer
-func (*Encoder) WriteInlines(w io.Writer, is *ast.InlineSlice) (int, error) {
-	hobj, err := shtmlenc.TransformSlice(is)
+func (he *Encoder) WriteInlines(w io.Writer, is *ast.InlineSlice) (int, error) {
+	hobj, err := he.th.Transform(he.tx.GetSz(is))
 	if err == nil {
 		gen := sxhtml.NewGenerator(sxpf.FindSymbolFactory(hobj))
 		length, err2 := gen.WriteListHTML(w, hobj)
 		if err2 != nil {
 			return length, err2

Index: encoder/mdenc/mdenc.go
==================================================================
--- encoder/mdenc/mdenc.go
+++ encoder/mdenc/mdenc.go
@@ -14,12 +14,12 @@
 import (
 	"io"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	encoder.Register(api.EncoderMD, func() encoder.Encoder { return Create() })
 }

DELETED encoder/sexprenc/sexprenc.go
Index: encoder/sexprenc/sexprenc.go
==================================================================
--- encoder/sexprenc/sexprenc.go
+++ encoder/sexprenc/sexprenc.go
@@ -1,63 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2022-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-// Package sexprenc encodes the abstract syntax tree into a s-expr.
-package sexprenc
-
-import (
-	"io"
-
-	"codeberg.org/t73fde/sxpf"
-	"zettelstore.de/c/api"
-	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
-	"zettelstore.de/z/encoder"
-)
-
-func init() {
-	encoder.Register(api.EncoderSexpr, func() encoder.Encoder { return Create() })
-}
-
-// Create a S-expr encoder
-func Create() *Encoder { return &mySE }
-
-type Encoder struct{}
-
-var mySE Encoder
-
-// WriteZettel writes the encoded zettel to the writer.
-func (*Encoder) WriteZettel(w io.Writer, zn *ast.ZettelNode, evalMeta encoder.EvalMetaFunc) (int, error) {
-	t := NewTransformer()
-	content := t.GetSexpr(&zn.Ast)
-	meta := t.GetMeta(zn.InhMeta, evalMeta)
-	return io.WriteString(w, sxpf.Nil().Cons(content).Cons(meta).Repr())
-}
-
-// WriteMeta encodes meta data as s-expression.
-func (*Encoder) WriteMeta(w io.Writer, m *meta.Meta, evalMeta encoder.EvalMetaFunc) (int, error) {
-	t := NewTransformer()
-	return io.WriteString(w, t.GetMeta(m, evalMeta).Repr())
-}
-
-func (se *Encoder) WriteContent(w io.Writer, zn *ast.ZettelNode) (int, error) {
-	return se.WriteBlocks(w, &zn.Ast)
-}
-
-// WriteBlocks writes a block slice to the writer
-func (*Encoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
-	t := NewTransformer()
-	return io.WriteString(w, t.GetSexpr(bs).Repr())
-}
-
-// WriteInlines writes an inline slice to the writer
-func (*Encoder) WriteInlines(w io.Writer, is *ast.InlineSlice) (int, error) {
-	t := NewTransformer()
-	return io.WriteString(w, t.GetSexpr(is).Repr())
-}

DELETED encoder/sexprenc/transform.go
Index: encoder/sexprenc/transform.go
==================================================================
--- encoder/sexprenc/transform.go
+++ encoder/sexprenc/transform.go
@@ -1,430 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2022-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package sexprenc
-
-import (
-	"encoding/base64"
-	"fmt"
-	"log"
-	"strings"
-
-	"codeberg.org/t73fde/sxpf"
-	"zettelstore.de/c/attrs"
-	"zettelstore.de/c/sexpr"
-	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
-	"zettelstore.de/z/encoder"
-)
-
-// NewTransformer returns a new transformer to create s-expressions from AST nodes.
-func NewTransformer() *Transformer {
-	sf := sxpf.MakeMappedFactory()
-	t := Transformer{sf: sf}
-	t.zetSyms.InitializeZettelSymbols(sf)
-
-	t.mapVerbatimKindS = map[ast.VerbatimKind]*sxpf.Symbol{
-		ast.VerbatimZettel:  t.zetSyms.SymVerbatimZettel,
-		ast.VerbatimProg:    t.zetSyms.SymVerbatimProg,
-		ast.VerbatimEval:    t.zetSyms.SymVerbatimEval,
-		ast.VerbatimMath:    t.zetSyms.SymVerbatimMath,
-		ast.VerbatimComment: t.zetSyms.SymVerbatimComment,
-		ast.VerbatimHTML:    t.zetSyms.SymVerbatimHTML,
-	}
-
-	t.mapRegionKindS = map[ast.RegionKind]*sxpf.Symbol{
-		ast.RegionSpan:  t.zetSyms.SymRegionBlock,
-		ast.RegionQuote: t.zetSyms.SymRegionQuote,
-		ast.RegionVerse: t.zetSyms.SymRegionVerse,
-	}
-	t.mapNestedListKindS = map[ast.NestedListKind]*sxpf.Symbol{
-		ast.NestedListOrdered:   t.zetSyms.SymListOrdered,
-		ast.NestedListUnordered: t.zetSyms.SymListUnordered,
-		ast.NestedListQuote:     t.zetSyms.SymListQuote,
-	}
-	t.alignmentSymbolS = map[ast.Alignment]*sxpf.Symbol{
-		ast.AlignDefault: t.zetSyms.SymCell,
-		ast.AlignLeft:    t.zetSyms.SymCellLeft,
-		ast.AlignCenter:  t.zetSyms.SymCellCenter,
-		ast.AlignRight:   t.zetSyms.SymCellRight,
-	}
-	t.mapRefStateLink = map[ast.RefState]*sxpf.Symbol{
-		ast.RefStateInvalid:  t.zetSyms.SymLinkInvalid,
-		ast.RefStateZettel:   t.zetSyms.SymLinkZettel,
-		ast.RefStateSelf:     t.zetSyms.SymLinkSelf,
-		ast.RefStateFound:    t.zetSyms.SymLinkFound,
-		ast.RefStateBroken:   t.zetSyms.SymLinkBroken,
-		ast.RefStateHosted:   t.zetSyms.SymLinkHosted,
-		ast.RefStateBased:    t.zetSyms.SymLinkBased,
-		ast.RefStateQuery:    t.zetSyms.SymLinkQuery,
-		ast.RefStateExternal: t.zetSyms.SymLinkExternal,
-	}
-	t.mapFormatKindS = map[ast.FormatKind]*sxpf.Symbol{
-		ast.FormatEmph:   t.zetSyms.SymFormatEmph,
-		ast.FormatStrong: t.zetSyms.SymFormatStrong,
-		ast.FormatDelete: t.zetSyms.SymFormatDelete,
-		ast.FormatInsert: t.zetSyms.SymFormatInsert,
-		ast.FormatSuper:  t.zetSyms.SymFormatSuper,
-		ast.FormatSub:    t.zetSyms.SymFormatSub,
-		ast.FormatQuote:  t.zetSyms.SymFormatQuote,
-		ast.FormatSpan:   t.zetSyms.SymFormatSpan,
-	}
-	t.mapLiteralKindS = map[ast.LiteralKind]*sxpf.Symbol{
-		ast.LiteralZettel:  t.zetSyms.SymLiteralZettel,
-		ast.LiteralProg:    t.zetSyms.SymLiteralProg,
-		ast.LiteralInput:   t.zetSyms.SymLiteralInput,
-		ast.LiteralOutput:  t.zetSyms.SymLiteralOutput,
-		ast.LiteralComment: t.zetSyms.SymLiteralComment,
-		ast.LiteralHTML:    t.zetSyms.SymLiteralHTML,
-		ast.LiteralMath:    t.zetSyms.SymLiteralMath,
-	}
-	t.mapRefStateS = map[ast.RefState]*sxpf.Symbol{
-		ast.RefStateInvalid:  t.zetSyms.SymRefStateInvalid,
-		ast.RefStateZettel:   t.zetSyms.SymRefStateZettel,
-		ast.RefStateSelf:     t.zetSyms.SymRefStateSelf,
-		ast.RefStateFound:    t.zetSyms.SymRefStateFound,
-		ast.RefStateBroken:   t.zetSyms.SymRefStateBroken,
-		ast.RefStateHosted:   t.zetSyms.SymRefStateHosted,
-		ast.RefStateBased:    t.zetSyms.SymRefStateBased,
-		ast.RefStateQuery:    t.zetSyms.SymRefStateQuery,
-		ast.RefStateExternal: t.zetSyms.SymRefStateExternal,
-	}
-	t.mapMetaTypeS = map[*meta.DescriptionType]*sxpf.Symbol{
-		meta.TypeCredential:   t.zetSyms.SymTypeCredential,
-		meta.TypeEmpty:        t.zetSyms.SymTypeEmpty,
-		meta.TypeID:           t.zetSyms.SymTypeID,
-		meta.TypeIDSet:        t.zetSyms.SymTypeIDSet,
-		meta.TypeNumber:       t.zetSyms.SymTypeNumber,
-		meta.TypeString:       t.zetSyms.SymTypeString,
-		meta.TypeTagSet:       t.zetSyms.SymTypeTagSet,
-		meta.TypeTimestamp:    t.zetSyms.SymTypeTimestamp,
-		meta.TypeURL:          t.zetSyms.SymTypeURL,
-		meta.TypeWord:         t.zetSyms.SymTypeWord,
-		meta.TypeWordSet:      t.zetSyms.SymTypeWordSet,
-		meta.TypeZettelmarkup: t.zetSyms.SymTypeZettelmarkup,
-	}
-	return &t
-}
-
-type Transformer struct {
-	sf                 sxpf.SymbolFactory
-	zetSyms            sexpr.ZettelSymbols
-	mapVerbatimKindS   map[ast.VerbatimKind]*sxpf.Symbol
-	mapRegionKindS     map[ast.RegionKind]*sxpf.Symbol
-	mapNestedListKindS map[ast.NestedListKind]*sxpf.Symbol
-	alignmentSymbolS   map[ast.Alignment]*sxpf.Symbol
-	mapRefStateLink    map[ast.RefState]*sxpf.Symbol
-	mapFormatKindS     map[ast.FormatKind]*sxpf.Symbol
-	mapLiteralKindS    map[ast.LiteralKind]*sxpf.Symbol
-	mapRefStateS       map[ast.RefState]*sxpf.Symbol
-	mapMetaTypeS       map[*meta.DescriptionType]*sxpf.Symbol
-	inVerse            bool
-}
-
-func (t *Transformer) GetSexpr(node ast.Node) *sxpf.List {
-	switch n := node.(type) {
-	case *ast.BlockSlice:
-		return t.getBlockSlice(n)
-	case *ast.InlineSlice:
-		return t.getInlineSlice(*n)
-	case *ast.ParaNode:
-		return t.getInlineSlice(n.Inlines).Tail().Cons(t.zetSyms.SymPara)
-	case *ast.VerbatimNode:
-		return sxpf.MakeList(
-			mapGetS(t, t.mapVerbatimKindS, n.Kind),
-			t.getAttributes(n.Attrs),
-			sxpf.MakeString(string(n.Content)),
-		)
-	case *ast.RegionNode:
-		return t.getRegion(n)
-	case *ast.HeadingNode:
-		return sxpf.MakeList(
-			t.zetSyms.SymHeading,
-			sxpf.MakeInteger64(int64(n.Level)),
-			t.getAttributes(n.Attrs),
-			sxpf.MakeString(n.Slug),
-			sxpf.MakeString(n.Fragment),
-			t.getInlineSlice(n.Inlines),
-		)
-	case *ast.HRuleNode:
-		return sxpf.MakeList(t.zetSyms.SymThematic, t.getAttributes(n.Attrs))
-	case *ast.NestedListNode:
-		return t.getNestedList(n)
-	case *ast.DescriptionListNode:
-		return t.getDescriptionList(n)
-	case *ast.TableNode:
-		return t.getTable(n)
-	case *ast.TranscludeNode:
-		return sxpf.MakeList(t.zetSyms.SymTransclude, t.getAttributes(n.Attrs), t.getReference(n.Ref))
-	case *ast.BLOBNode:
-		return t.getBLOB(n)
-	case *ast.TextNode:
-		return sxpf.MakeList(t.zetSyms.SymText, sxpf.MakeString(n.Text))
-	case *ast.SpaceNode:
-		if t.inVerse {
-			return sxpf.MakeList(t.zetSyms.SymSpace, sxpf.MakeString(n.Lexeme))
-		}
-		return sxpf.MakeList(t.zetSyms.SymSpace)
-	case *ast.BreakNode:
-		if n.Hard {
-			return sxpf.MakeList(t.zetSyms.SymHard)
-		}
-		return sxpf.MakeList(t.zetSyms.SymSoft)
-	case *ast.LinkNode:
-		return t.getLink(n)
-	case *ast.EmbedRefNode:
-		return t.getInlineSlice(n.Inlines).Tail().
-			Cons(sxpf.MakeString(n.Syntax)).
-			Cons(t.getReference(n.Ref)).
-			Cons(t.getAttributes(n.Attrs)).
-			Cons(t.zetSyms.SymEmbed)
-	case *ast.EmbedBLOBNode:
-		return t.getEmbedBLOB(n)
-	case *ast.CiteNode:
-		return t.getInlineSlice(n.Inlines).Tail().
-			Cons(sxpf.MakeString(n.Key)).
-			Cons(t.getAttributes(n.Attrs)).
-			Cons(t.zetSyms.SymCite)
-	case *ast.FootnoteNode:
-		text := sxpf.Nil().Cons(sxpf.Nil().Cons(t.getInlineSlice(n.Inlines)).Cons(t.zetSyms.SymQuote))
-		return text.Cons(t.getAttributes(n.Attrs)).Cons(t.zetSyms.SymEndnote)
-	case *ast.MarkNode:
-		return t.getInlineSlice(n.Inlines).Tail().
-			Cons(sxpf.MakeString(n.Fragment)).
-			Cons(sxpf.MakeString(n.Slug)).
-			Cons(sxpf.MakeString(n.Mark)).
-			Cons(t.zetSyms.SymMark)
-	case *ast.FormatNode:
-		return t.getInlineSlice(n.Inlines).Tail().
-			Cons(t.getAttributes(n.Attrs)).
-			Cons(mapGetS(t, t.mapFormatKindS, n.Kind))
-	case *ast.LiteralNode:
-		return sxpf.MakeList(
-			mapGetS(t, t.mapLiteralKindS, n.Kind),
-			t.getAttributes(n.Attrs),
-			sxpf.MakeString(string(n.Content)),
-		)
-	}
-	log.Printf("SEXPR %T %v\n", node, node)
-	return sxpf.MakeList(t.zetSyms.SymUnknown, sxpf.MakeString(fmt.Sprintf("%T %v", node, node)))
-}
-
-func (t *Transformer) getRegion(rn *ast.RegionNode) *sxpf.List {
-	saveInVerse := t.inVerse
-	if rn.Kind == ast.RegionVerse {
-		t.inVerse = true
-	}
-	symBlocks := t.GetSexpr(&rn.Blocks)
-	t.inVerse = saveInVerse
-	return sxpf.MakeList(
-		mapGetS(t, t.mapRegionKindS, rn.Kind),
-		t.getAttributes(rn.Attrs),
-		symBlocks,
-		t.GetSexpr(&rn.Inlines),
-	)
-}
-
-func (t *Transformer) getNestedList(ln *ast.NestedListNode) *sxpf.List {
-	nlistObjs := make([]sxpf.Object, len(ln.Items)+1)
-	nlistObjs[0] = mapGetS(t, t.mapNestedListKindS, ln.Kind)
-	isCompact := isCompactList(ln.Items)
-	for i, item := range ln.Items {
-		if isCompact && len(item) > 0 {
-			paragraph := t.GetSexpr(item[0])
-			nlistObjs[i+1] = paragraph.Tail().Cons(t.zetSyms.SymInline)
-			continue
-		}
-		itemObjs := make([]sxpf.Object, len(item))
-		for j, in := range item {
-			itemObjs[j] = t.GetSexpr(in)
-		}
-		if isCompact {
-			nlistObjs[i+1] = sxpf.MakeList(itemObjs...).Cons(t.zetSyms.SymInline)
-		} else {
-			nlistObjs[i+1] = sxpf.MakeList(itemObjs...).Cons(t.zetSyms.SymBlock)
-		}
-	}
-	return sxpf.MakeList(nlistObjs...)
-}
-func isCompactList(itemSlice []ast.ItemSlice) bool {
-	for _, items := range itemSlice {
-		if len(items) > 1 {
-			return false
-		}
-		if len(items) == 1 {
-			if _, ok := items[0].(*ast.ParaNode); !ok {
-				return false
-			}
-		}
-	}
-	return true
-}
-
-func (t *Transformer) getDescriptionList(dn *ast.DescriptionListNode) *sxpf.List {
-	dlObjs := make([]sxpf.Object, 2*len(dn.Descriptions)+1)
-	dlObjs[0] = t.zetSyms.SymDescription
-	for i, def := range dn.Descriptions {
-		dlObjs[2*i+1] = t.getInlineSlice(def.Term)
-		descObjs := make([]sxpf.Object, len(def.Descriptions))
-		for j, b := range def.Descriptions {
-			dVal := make([]sxpf.Object, len(b))
-			for k, dn := range b {
-				dVal[k] = t.GetSexpr(dn)
-			}
-			descObjs[j] = sxpf.MakeList(dVal...).Cons(t.zetSyms.SymBlock)
-		}
-		dlObjs[2*i+2] = sxpf.MakeList(descObjs...).Cons(t.zetSyms.SymBlock)
-	}
-	return sxpf.MakeList(dlObjs...)
-}
-
-func (t *Transformer) getTable(tn *ast.TableNode) *sxpf.List {
-	tObjs := make([]sxpf.Object, len(tn.Rows)+2)
-	tObjs[0] = t.zetSyms.SymTable
-	tObjs[1] = t.getHeader(tn.Header)
-	for i, row := range tn.Rows {
-		tObjs[i+2] = t.getRow(row)
-	}
-	return sxpf.MakeList(tObjs...)
-}
-func (t *Transformer) getHeader(header ast.TableRow) *sxpf.List {
-	if len(header) == 0 {
-		return sxpf.Nil()
-	}
-	return t.getRow(header)
-}
-func (t *Transformer) getRow(row ast.TableRow) *sxpf.List {
-	rObjs := make([]sxpf.Object, len(row))
-	for i, cell := range row {
-		rObjs[i] = t.getCell(cell)
-	}
-	return sxpf.MakeList(rObjs...).Cons(t.zetSyms.SymList)
-}
-
-func (t *Transformer) getCell(cell *ast.TableCell) *sxpf.List {
-	return t.getInlineSlice(cell.Inlines).Tail().Cons(mapGetS(t, t.alignmentSymbolS, cell.Align))
-}
-
-func (t *Transformer) getBLOB(bn *ast.BLOBNode) *sxpf.List {
-	var lastObj sxpf.Object
-	if bn.Syntax == meta.SyntaxSVG {
-		lastObj = sxpf.MakeString(string(bn.Blob))
-	} else {
-		lastObj = getBase64String(bn.Blob)
-	}
-	return sxpf.MakeList(
-		t.zetSyms.SymBLOB,
-		t.getInlineSlice(bn.Description),
-		sxpf.MakeString(bn.Syntax),
-		lastObj,
-	)
-}
-
-func (t *Transformer) getLink(ln *ast.LinkNode) *sxpf.List {
-	return t.getInlineSlice(ln.Inlines).Tail().
-		Cons(sxpf.MakeString(ln.Ref.Value)).
-		Cons(t.getAttributes(ln.Attrs)).
-		Cons(mapGetS(t, t.mapRefStateLink, ln.Ref.State))
-}
-
-func (t *Transformer) getEmbedBLOB(en *ast.EmbedBLOBNode) *sxpf.List {
-	tail := t.getInlineSlice(en.Inlines).Tail()
-	if en.Syntax == meta.SyntaxSVG {
-		tail = tail.Cons(sxpf.MakeString(string(en.Blob)))
-	} else {
-		tail = tail.Cons(getBase64String(en.Blob))
-	}
-	return tail.Cons(sxpf.MakeString(en.Syntax)).Cons(t.getAttributes(en.Attrs)).Cons(t.zetSyms.SymEmbedBLOB)
-}
-
-func (t *Transformer) getBlockSlice(bs *ast.BlockSlice) *sxpf.List {
-	objs := make([]sxpf.Object, len(*bs))
-	for i, n := range *bs {
-		objs[i] = t.GetSexpr(n)
-	}
-	return sxpf.MakeList(objs...).Cons(t.zetSyms.SymBlock)
-}
-func (t *Transformer) getInlineSlice(is ast.InlineSlice) *sxpf.List {
-	objs := make([]sxpf.Object, len(is))
-	for i, n := range is {
-		objs[i] = t.GetSexpr(n)
-	}
-	return sxpf.MakeList(objs...).Cons(t.zetSyms.SymInline)
-}
-
-func (t *Transformer) getAttributes(a attrs.Attributes) sxpf.Object {
-	if a.IsEmpty() {
-		return sxpf.Nil()
-	}
-	keys := a.Keys()
-	objs := make([]sxpf.Object, 0, len(keys))
-	for _, k := range keys {
-		objs = append(objs, sxpf.Cons(sxpf.MakeString(k), sxpf.MakeString(a[k])))
-	}
-	return sxpf.Nil().Cons(sxpf.MakeList(objs...)).Cons(t.zetSyms.SymQuote)
-}
-
-func (t *Transformer) getReference(ref *ast.Reference) *sxpf.List {
-	return sxpf.MakeList(
-		t.zetSyms.SymQuote,
-		sxpf.MakeList(
-			mapGetS(t, t.mapRefStateS, ref.State),
-			sxpf.MakeString(ref.Value),
-		),
-	)
-}
-
-func (t *Transformer) GetMeta(m *meta.Meta, evalMeta encoder.EvalMetaFunc) *sxpf.List {
-	pairs := m.ComputedPairs()
-	objs := make([]sxpf.Object, 0, len(pairs))
-	for _, p := range pairs {
-		key := p.Key
-		ty := m.Type(key)
-		symType := mapGetS(t, t.mapMetaTypeS, ty)
-		strKey := sxpf.MakeString(key)
-		var obj sxpf.Object
-		if ty.IsSet {
-			setList := meta.ListFromValue(p.Value)
-			setObjs := make([]sxpf.Object, len(setList))
-			for i, val := range setList {
-				setObjs[i] = sxpf.MakeString(val)
-			}
-			obj = sxpf.MakeList(setObjs...).Cons(t.zetSyms.SymList)
-		} else if ty == meta.TypeZettelmarkup {
-			is := evalMeta(p.Value)
-			obj = t.GetSexpr(&is)
-		} else {
-			obj = sxpf.MakeString(p.Value)
-		}
-		objs = append(objs, sxpf.Nil().Cons(obj).Cons(strKey).Cons(symType))
-	}
-	return sxpf.MakeList(objs...).Cons(t.zetSyms.SymMeta)
-}
-
-func mapGetS[T comparable](t *Transformer, m map[T]*sxpf.Symbol, k T) *sxpf.Symbol {
-	if result, found := m[k]; found {
-		return result
-	}
-	log.Println("MISS", k, m)
-	return t.sf.MustMake(fmt.Sprintf("**%v:NOT-FOUND**", k))
-}
-
-func getBase64String(data []byte) sxpf.String {
-	var sb strings.Builder
-	encoder := base64.NewEncoder(base64.StdEncoding, &sb)
-	_, err := encoder.Write(data)
-	if err == nil {
-		err = encoder.Close()
-	}
-	if err == nil {
-		return sxpf.MakeString(sb.String())
-	}
-	return sxpf.MakeString("")
-}

Index: encoder/shtmlenc/shtmlenc.go
==================================================================
--- encoder/shtmlenc/shtmlenc.go
+++ encoder/shtmlenc/shtmlenc.go
@@ -16,77 +16,73 @@
 
 	"codeberg.org/t73fde/sxpf"
 	"zettelstore.de/c/api"
 	"zettelstore.de/c/shtml"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder"
-	"zettelstore.de/z/encoder/sexprenc"
+	"zettelstore.de/z/encoder/szenc"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	encoder.Register(api.EncoderSHTML, func() encoder.Encoder { return Create() })
 }
 
 // Create a SHTML encoder
-func Create() *Encoder { return &mySE }
-
-type Encoder struct{}
+func Create() *Encoder {
+	// We need a new transformer every time, because tx.inVerse must be unique.
+	// If we can refactor it out, the transformer can be created only once.
+	return &Encoder{
+		tx: szenc.NewTransformer(),
+		th: shtml.NewTransformer(1, nil),
+	}
+}
 
-var mySE Encoder
+type Encoder struct {
+	tx *szenc.Transformer
+	th *shtml.Transformer
+}
 
 // WriteZettel writes the encoded zettel to the writer.
-func (*Encoder) WriteZettel(w io.Writer, zn *ast.ZettelNode, evalMeta encoder.EvalMetaFunc) (int, error) {
-	tx := sexprenc.NewTransformer()
-	th := shtml.NewTransformer(1, nil)
-	metaSHTML, err := th.Transform(tx.GetMeta(zn.InhMeta, evalMeta))
+func (enc *Encoder) WriteZettel(w io.Writer, zn *ast.ZettelNode, evalMeta encoder.EvalMetaFunc) (int, error) {
+	metaSHTML, err := enc.th.Transform(enc.tx.GetMeta(zn.InhMeta, evalMeta))
 	if err != nil {
 		return 0, err
 	}
-	contentSHTML, err := th.Transform(tx.GetSexpr(&zn.Ast))
+	contentSHTML, err := enc.th.Transform(enc.tx.GetSz(&zn.Ast))
 	if err != nil {
 		return 0, err
 	}
 	result := sxpf.Cons(metaSHTML, contentSHTML)
 	return result.Print(w)
 }
 
 // WriteMeta encodes meta data as s-expression.
-func (*Encoder) WriteMeta(w io.Writer, m *meta.Meta, evalMeta encoder.EvalMetaFunc) (int, error) {
-	tx := sexprenc.NewTransformer()
-	th := shtml.NewTransformer(1, nil)
-	metaSHTML, err := th.Transform(tx.GetMeta(m, evalMeta))
+func (enc *Encoder) WriteMeta(w io.Writer, m *meta.Meta, evalMeta encoder.EvalMetaFunc) (int, error) {
+	metaSHTML, err := enc.th.Transform(enc.tx.GetMeta(m, evalMeta))
 	if err != nil {
 		return 0, err
 	}
 	return metaSHTML.Print(w)
 }
 
-func (se *Encoder) WriteContent(w io.Writer, zn *ast.ZettelNode) (int, error) {
-	return se.WriteBlocks(w, &zn.Ast)
+func (enc *Encoder) WriteContent(w io.Writer, zn *ast.ZettelNode) (int, error) {
+	return enc.WriteBlocks(w, &zn.Ast)
 }
 
 // WriteBlocks writes a block slice to the writer
-func (*Encoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
-	hval, err := TransformSlice(bs)
+func (enc *Encoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
+	hval, err := enc.th.Transform(enc.tx.GetSz(bs))
 	if err != nil {
 		return 0, err
 	}
 	return hval.Print(w)
 }
 
 // WriteInlines writes an inline slice to the writer
-func (*Encoder) WriteInlines(w io.Writer, is *ast.InlineSlice) (int, error) {
-	hval, err := TransformSlice(is)
+func (enc *Encoder) WriteInlines(w io.Writer, is *ast.InlineSlice) (int, error) {
+	hval, err := enc.th.Transform(enc.tx.GetSz(is))
 	if err != nil {
 		return 0, err
 	}
 	return hval.Print(w)
 }
-
-// TransformSlice transforms a AST slice into SHTML.
-func TransformSlice(node ast.Node) (*sxpf.List, error) {
-	tx := sexprenc.NewTransformer()
-	xval := tx.GetSexpr(node)
-	th := shtml.NewTransformer(1, nil)
-	return th.Transform(xval)
-}

ADDED   encoder/szenc/szenc.go
Index: encoder/szenc/szenc.go
==================================================================
--- encoder/szenc/szenc.go
+++ encoder/szenc/szenc.go
@@ -0,0 +1,63 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2022-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+// Package szenc encodes the abstract syntax tree into a s-expr for zettel.
+package szenc
+
+import (
+	"io"
+
+	"codeberg.org/t73fde/sxpf"
+	"zettelstore.de/c/api"
+	"zettelstore.de/z/ast"
+	"zettelstore.de/z/encoder"
+	"zettelstore.de/z/zettel/meta"
+)
+
+func init() {
+	encoder.Register(api.EncoderSz, func() encoder.Encoder { return Create() })
+}
+
+// Create a S-expr encoder
+func Create() *Encoder {
+	// We need a new transformer every time, because trans.inVerse must be unique.
+	// If we can refactor it out, the transformer can be created only once.
+	return &Encoder{trans: NewTransformer()}
+}
+
+type Encoder struct {
+	trans *Transformer
+}
+
+// WriteZettel writes the encoded zettel to the writer.
+func (enc *Encoder) WriteZettel(w io.Writer, zn *ast.ZettelNode, evalMeta encoder.EvalMetaFunc) (int, error) {
+	content := enc.trans.GetSz(&zn.Ast)
+	meta := enc.trans.GetMeta(zn.InhMeta, evalMeta)
+	return sxpf.MakeList(meta, content).Print(w)
+}
+
+// WriteMeta encodes meta data as s-expression.
+func (enc *Encoder) WriteMeta(w io.Writer, m *meta.Meta, evalMeta encoder.EvalMetaFunc) (int, error) {
+	return enc.trans.GetMeta(m, evalMeta).Print(w)
+}
+
+func (enc *Encoder) WriteContent(w io.Writer, zn *ast.ZettelNode) (int, error) {
+	return enc.WriteBlocks(w, &zn.Ast)
+}
+
+// WriteBlocks writes a block slice to the writer
+func (enc *Encoder) WriteBlocks(w io.Writer, bs *ast.BlockSlice) (int, error) {
+	return enc.trans.GetSz(bs).Print(w)
+}
+
+// WriteInlines writes an inline slice to the writer
+func (enc *Encoder) WriteInlines(w io.Writer, is *ast.InlineSlice) (int, error) {
+	return enc.trans.GetSz(is).Print(w)
+}

ADDED   encoder/szenc/transform.go
Index: encoder/szenc/transform.go
==================================================================
--- encoder/szenc/transform.go
+++ encoder/szenc/transform.go
@@ -0,0 +1,427 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2022-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package szenc
+
+import (
+	"encoding/base64"
+	"fmt"
+	"strings"
+
+	"codeberg.org/t73fde/sxpf"
+	"zettelstore.de/c/attrs"
+	"zettelstore.de/c/sz"
+	"zettelstore.de/z/ast"
+	"zettelstore.de/z/encoder"
+	"zettelstore.de/z/zettel/meta"
+)
+
+// NewTransformer returns a new transformer to create s-expressions from AST nodes.
+func NewTransformer() *Transformer {
+	sf := sxpf.MakeMappedFactory()
+	t := Transformer{sf: sf}
+	t.zetSyms.InitializeZettelSymbols(sf)
+
+	t.mapVerbatimKindS = map[ast.VerbatimKind]*sxpf.Symbol{
+		ast.VerbatimZettel:  t.zetSyms.SymVerbatimZettel,
+		ast.VerbatimProg:    t.zetSyms.SymVerbatimProg,
+		ast.VerbatimEval:    t.zetSyms.SymVerbatimEval,
+		ast.VerbatimMath:    t.zetSyms.SymVerbatimMath,
+		ast.VerbatimComment: t.zetSyms.SymVerbatimComment,
+		ast.VerbatimHTML:    t.zetSyms.SymVerbatimHTML,
+	}
+
+	t.mapRegionKindS = map[ast.RegionKind]*sxpf.Symbol{
+		ast.RegionSpan:  t.zetSyms.SymRegionBlock,
+		ast.RegionQuote: t.zetSyms.SymRegionQuote,
+		ast.RegionVerse: t.zetSyms.SymRegionVerse,
+	}
+	t.mapNestedListKindS = map[ast.NestedListKind]*sxpf.Symbol{
+		ast.NestedListOrdered:   t.zetSyms.SymListOrdered,
+		ast.NestedListUnordered: t.zetSyms.SymListUnordered,
+		ast.NestedListQuote:     t.zetSyms.SymListQuote,
+	}
+	t.alignmentSymbolS = map[ast.Alignment]*sxpf.Symbol{
+		ast.AlignDefault: t.zetSyms.SymCell,
+		ast.AlignLeft:    t.zetSyms.SymCellLeft,
+		ast.AlignCenter:  t.zetSyms.SymCellCenter,
+		ast.AlignRight:   t.zetSyms.SymCellRight,
+	}
+	t.mapRefStateLink = map[ast.RefState]*sxpf.Symbol{
+		ast.RefStateInvalid:  t.zetSyms.SymLinkInvalid,
+		ast.RefStateZettel:   t.zetSyms.SymLinkZettel,
+		ast.RefStateSelf:     t.zetSyms.SymLinkSelf,
+		ast.RefStateFound:    t.zetSyms.SymLinkFound,
+		ast.RefStateBroken:   t.zetSyms.SymLinkBroken,
+		ast.RefStateHosted:   t.zetSyms.SymLinkHosted,
+		ast.RefStateBased:    t.zetSyms.SymLinkBased,
+		ast.RefStateQuery:    t.zetSyms.SymLinkQuery,
+		ast.RefStateExternal: t.zetSyms.SymLinkExternal,
+	}
+	t.mapFormatKindS = map[ast.FormatKind]*sxpf.Symbol{
+		ast.FormatEmph:   t.zetSyms.SymFormatEmph,
+		ast.FormatStrong: t.zetSyms.SymFormatStrong,
+		ast.FormatDelete: t.zetSyms.SymFormatDelete,
+		ast.FormatInsert: t.zetSyms.SymFormatInsert,
+		ast.FormatSuper:  t.zetSyms.SymFormatSuper,
+		ast.FormatSub:    t.zetSyms.SymFormatSub,
+		ast.FormatQuote:  t.zetSyms.SymFormatQuote,
+		ast.FormatSpan:   t.zetSyms.SymFormatSpan,
+	}
+	t.mapLiteralKindS = map[ast.LiteralKind]*sxpf.Symbol{
+		ast.LiteralZettel:  t.zetSyms.SymLiteralZettel,
+		ast.LiteralProg:    t.zetSyms.SymLiteralProg,
+		ast.LiteralInput:   t.zetSyms.SymLiteralInput,
+		ast.LiteralOutput:  t.zetSyms.SymLiteralOutput,
+		ast.LiteralComment: t.zetSyms.SymLiteralComment,
+		ast.LiteralHTML:    t.zetSyms.SymLiteralHTML,
+		ast.LiteralMath:    t.zetSyms.SymLiteralMath,
+	}
+	t.mapRefStateS = map[ast.RefState]*sxpf.Symbol{
+		ast.RefStateInvalid:  t.zetSyms.SymRefStateInvalid,
+		ast.RefStateZettel:   t.zetSyms.SymRefStateZettel,
+		ast.RefStateSelf:     t.zetSyms.SymRefStateSelf,
+		ast.RefStateFound:    t.zetSyms.SymRefStateFound,
+		ast.RefStateBroken:   t.zetSyms.SymRefStateBroken,
+		ast.RefStateHosted:   t.zetSyms.SymRefStateHosted,
+		ast.RefStateBased:    t.zetSyms.SymRefStateBased,
+		ast.RefStateQuery:    t.zetSyms.SymRefStateQuery,
+		ast.RefStateExternal: t.zetSyms.SymRefStateExternal,
+	}
+	t.mapMetaTypeS = map[*meta.DescriptionType]*sxpf.Symbol{
+		meta.TypeCredential:   t.zetSyms.SymTypeCredential,
+		meta.TypeEmpty:        t.zetSyms.SymTypeEmpty,
+		meta.TypeID:           t.zetSyms.SymTypeID,
+		meta.TypeIDSet:        t.zetSyms.SymTypeIDSet,
+		meta.TypeNumber:       t.zetSyms.SymTypeNumber,
+		meta.TypeString:       t.zetSyms.SymTypeString,
+		meta.TypeTagSet:       t.zetSyms.SymTypeTagSet,
+		meta.TypeTimestamp:    t.zetSyms.SymTypeTimestamp,
+		meta.TypeURL:          t.zetSyms.SymTypeURL,
+		meta.TypeWord:         t.zetSyms.SymTypeWord,
+		meta.TypeWordSet:      t.zetSyms.SymTypeWordSet,
+		meta.TypeZettelmarkup: t.zetSyms.SymTypeZettelmarkup,
+	}
+	return &t
+}
+
+type Transformer struct {
+	sf                 sxpf.SymbolFactory
+	zetSyms            sz.ZettelSymbols
+	mapVerbatimKindS   map[ast.VerbatimKind]*sxpf.Symbol
+	mapRegionKindS     map[ast.RegionKind]*sxpf.Symbol
+	mapNestedListKindS map[ast.NestedListKind]*sxpf.Symbol
+	alignmentSymbolS   map[ast.Alignment]*sxpf.Symbol
+	mapRefStateLink    map[ast.RefState]*sxpf.Symbol
+	mapFormatKindS     map[ast.FormatKind]*sxpf.Symbol
+	mapLiteralKindS    map[ast.LiteralKind]*sxpf.Symbol
+	mapRefStateS       map[ast.RefState]*sxpf.Symbol
+	mapMetaTypeS       map[*meta.DescriptionType]*sxpf.Symbol
+	inVerse            bool
+}
+
+func (t *Transformer) GetSz(node ast.Node) *sxpf.List {
+	switch n := node.(type) {
+	case *ast.BlockSlice:
+		return t.getBlockSlice(n)
+	case *ast.InlineSlice:
+		return t.getInlineSlice(*n)
+	case *ast.ParaNode:
+		return t.getInlineSlice(n.Inlines).Tail().Cons(t.zetSyms.SymPara)
+	case *ast.VerbatimNode:
+		return sxpf.MakeList(
+			mapGetS(t, t.mapVerbatimKindS, n.Kind),
+			t.getAttributes(n.Attrs),
+			sxpf.MakeString(string(n.Content)),
+		)
+	case *ast.RegionNode:
+		return t.getRegion(n)
+	case *ast.HeadingNode:
+		return sxpf.MakeList(
+			t.zetSyms.SymHeading,
+			sxpf.Int64(int64(n.Level)),
+			t.getAttributes(n.Attrs),
+			sxpf.MakeString(n.Slug),
+			sxpf.MakeString(n.Fragment),
+			t.getInlineSlice(n.Inlines),
+		)
+	case *ast.HRuleNode:
+		return sxpf.MakeList(t.zetSyms.SymThematic, t.getAttributes(n.Attrs))
+	case *ast.NestedListNode:
+		return t.getNestedList(n)
+	case *ast.DescriptionListNode:
+		return t.getDescriptionList(n)
+	case *ast.TableNode:
+		return t.getTable(n)
+	case *ast.TranscludeNode:
+		return sxpf.MakeList(t.zetSyms.SymTransclude, t.getAttributes(n.Attrs), t.getReference(n.Ref))
+	case *ast.BLOBNode:
+		return t.getBLOB(n)
+	case *ast.TextNode:
+		return sxpf.MakeList(t.zetSyms.SymText, sxpf.MakeString(n.Text))
+	case *ast.SpaceNode:
+		if t.inVerse {
+			return sxpf.MakeList(t.zetSyms.SymSpace, sxpf.MakeString(n.Lexeme))
+		}
+		return sxpf.MakeList(t.zetSyms.SymSpace)
+	case *ast.BreakNode:
+		if n.Hard {
+			return sxpf.MakeList(t.zetSyms.SymHard)
+		}
+		return sxpf.MakeList(t.zetSyms.SymSoft)
+	case *ast.LinkNode:
+		return t.getLink(n)
+	case *ast.EmbedRefNode:
+		return t.getInlineSlice(n.Inlines).Tail().
+			Cons(sxpf.MakeString(n.Syntax)).
+			Cons(t.getReference(n.Ref)).
+			Cons(t.getAttributes(n.Attrs)).
+			Cons(t.zetSyms.SymEmbed)
+	case *ast.EmbedBLOBNode:
+		return t.getEmbedBLOB(n)
+	case *ast.CiteNode:
+		return t.getInlineSlice(n.Inlines).Tail().
+			Cons(sxpf.MakeString(n.Key)).
+			Cons(t.getAttributes(n.Attrs)).
+			Cons(t.zetSyms.SymCite)
+	case *ast.FootnoteNode:
+		text := sxpf.Nil().Cons(sxpf.Nil().Cons(t.getInlineSlice(n.Inlines)).Cons(t.zetSyms.SymQuote))
+		return text.Cons(t.getAttributes(n.Attrs)).Cons(t.zetSyms.SymEndnote)
+	case *ast.MarkNode:
+		return t.getInlineSlice(n.Inlines).Tail().
+			Cons(sxpf.MakeString(n.Fragment)).
+			Cons(sxpf.MakeString(n.Slug)).
+			Cons(sxpf.MakeString(n.Mark)).
+			Cons(t.zetSyms.SymMark)
+	case *ast.FormatNode:
+		return t.getInlineSlice(n.Inlines).Tail().
+			Cons(t.getAttributes(n.Attrs)).
+			Cons(mapGetS(t, t.mapFormatKindS, n.Kind))
+	case *ast.LiteralNode:
+		return sxpf.MakeList(
+			mapGetS(t, t.mapLiteralKindS, n.Kind),
+			t.getAttributes(n.Attrs),
+			sxpf.MakeString(string(n.Content)),
+		)
+	}
+	return sxpf.MakeList(t.zetSyms.SymUnknown, sxpf.MakeString(fmt.Sprintf("%T %v", node, node)))
+}
+
+func (t *Transformer) getRegion(rn *ast.RegionNode) *sxpf.List {
+	saveInVerse := t.inVerse
+	if rn.Kind == ast.RegionVerse {
+		t.inVerse = true
+	}
+	symBlocks := t.GetSz(&rn.Blocks)
+	t.inVerse = saveInVerse
+	return sxpf.MakeList(
+		mapGetS(t, t.mapRegionKindS, rn.Kind),
+		t.getAttributes(rn.Attrs),
+		symBlocks,
+		t.GetSz(&rn.Inlines),
+	)
+}
+
+func (t *Transformer) getNestedList(ln *ast.NestedListNode) *sxpf.List {
+	nlistObjs := make([]sxpf.Object, len(ln.Items)+1)
+	nlistObjs[0] = mapGetS(t, t.mapNestedListKindS, ln.Kind)
+	isCompact := isCompactList(ln.Items)
+	for i, item := range ln.Items {
+		if isCompact && len(item) > 0 {
+			paragraph := t.GetSz(item[0])
+			nlistObjs[i+1] = paragraph.Tail().Cons(t.zetSyms.SymInline)
+			continue
+		}
+		itemObjs := make([]sxpf.Object, len(item))
+		for j, in := range item {
+			itemObjs[j] = t.GetSz(in)
+		}
+		if isCompact {
+			nlistObjs[i+1] = sxpf.MakeList(itemObjs...).Cons(t.zetSyms.SymInline)
+		} else {
+			nlistObjs[i+1] = sxpf.MakeList(itemObjs...).Cons(t.zetSyms.SymBlock)
+		}
+	}
+	return sxpf.MakeList(nlistObjs...)
+}
+func isCompactList(itemSlice []ast.ItemSlice) bool {
+	for _, items := range itemSlice {
+		if len(items) > 1 {
+			return false
+		}
+		if len(items) == 1 {
+			if _, ok := items[0].(*ast.ParaNode); !ok {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+func (t *Transformer) getDescriptionList(dn *ast.DescriptionListNode) *sxpf.List {
+	dlObjs := make([]sxpf.Object, 2*len(dn.Descriptions)+1)
+	dlObjs[0] = t.zetSyms.SymDescription
+	for i, def := range dn.Descriptions {
+		dlObjs[2*i+1] = t.getInlineSlice(def.Term)
+		descObjs := make([]sxpf.Object, len(def.Descriptions))
+		for j, b := range def.Descriptions {
+			dVal := make([]sxpf.Object, len(b))
+			for k, dn := range b {
+				dVal[k] = t.GetSz(dn)
+			}
+			descObjs[j] = sxpf.MakeList(dVal...).Cons(t.zetSyms.SymBlock)
+		}
+		dlObjs[2*i+2] = sxpf.MakeList(descObjs...).Cons(t.zetSyms.SymBlock)
+	}
+	return sxpf.MakeList(dlObjs...)
+}
+
+func (t *Transformer) getTable(tn *ast.TableNode) *sxpf.List {
+	tObjs := make([]sxpf.Object, len(tn.Rows)+2)
+	tObjs[0] = t.zetSyms.SymTable
+	tObjs[1] = t.getHeader(tn.Header)
+	for i, row := range tn.Rows {
+		tObjs[i+2] = t.getRow(row)
+	}
+	return sxpf.MakeList(tObjs...)
+}
+func (t *Transformer) getHeader(header ast.TableRow) *sxpf.List {
+	if len(header) == 0 {
+		return sxpf.Nil()
+	}
+	return t.getRow(header)
+}
+func (t *Transformer) getRow(row ast.TableRow) *sxpf.List {
+	rObjs := make([]sxpf.Object, len(row))
+	for i, cell := range row {
+		rObjs[i] = t.getCell(cell)
+	}
+	return sxpf.MakeList(rObjs...).Cons(t.zetSyms.SymList)
+}
+
+func (t *Transformer) getCell(cell *ast.TableCell) *sxpf.List {
+	return t.getInlineSlice(cell.Inlines).Tail().Cons(mapGetS(t, t.alignmentSymbolS, cell.Align))
+}
+
+func (t *Transformer) getBLOB(bn *ast.BLOBNode) *sxpf.List {
+	var lastObj sxpf.Object
+	if bn.Syntax == meta.SyntaxSVG {
+		lastObj = sxpf.MakeString(string(bn.Blob))
+	} else {
+		lastObj = getBase64String(bn.Blob)
+	}
+	return sxpf.MakeList(
+		t.zetSyms.SymBLOB,
+		t.getInlineSlice(bn.Description),
+		sxpf.MakeString(bn.Syntax),
+		lastObj,
+	)
+}
+
+func (t *Transformer) getLink(ln *ast.LinkNode) *sxpf.List {
+	return t.getInlineSlice(ln.Inlines).Tail().
+		Cons(sxpf.MakeString(ln.Ref.Value)).
+		Cons(t.getAttributes(ln.Attrs)).
+		Cons(mapGetS(t, t.mapRefStateLink, ln.Ref.State))
+}
+
+func (t *Transformer) getEmbedBLOB(en *ast.EmbedBLOBNode) *sxpf.List {
+	tail := t.getInlineSlice(en.Inlines).Tail()
+	if en.Syntax == meta.SyntaxSVG {
+		tail = tail.Cons(sxpf.MakeString(string(en.Blob)))
+	} else {
+		tail = tail.Cons(getBase64String(en.Blob))
+	}
+	return tail.Cons(sxpf.MakeString(en.Syntax)).Cons(t.getAttributes(en.Attrs)).Cons(t.zetSyms.SymEmbedBLOB)
+}
+
+func (t *Transformer) getBlockSlice(bs *ast.BlockSlice) *sxpf.List {
+	objs := make([]sxpf.Object, len(*bs))
+	for i, n := range *bs {
+		objs[i] = t.GetSz(n)
+	}
+	return sxpf.MakeList(objs...).Cons(t.zetSyms.SymBlock)
+}
+func (t *Transformer) getInlineSlice(is ast.InlineSlice) *sxpf.List {
+	objs := make([]sxpf.Object, len(is))
+	for i, n := range is {
+		objs[i] = t.GetSz(n)
+	}
+	return sxpf.MakeList(objs...).Cons(t.zetSyms.SymInline)
+}
+
+func (t *Transformer) getAttributes(a attrs.Attributes) sxpf.Object {
+	if a.IsEmpty() {
+		return sxpf.Nil()
+	}
+	keys := a.Keys()
+	objs := make([]sxpf.Object, 0, len(keys))
+	for _, k := range keys {
+		objs = append(objs, sxpf.Cons(sxpf.MakeString(k), sxpf.MakeString(a[k])))
+	}
+	return sxpf.Nil().Cons(sxpf.MakeList(objs...)).Cons(t.zetSyms.SymQuote)
+}
+
+func (t *Transformer) getReference(ref *ast.Reference) *sxpf.List {
+	return sxpf.MakeList(
+		t.zetSyms.SymQuote,
+		sxpf.MakeList(
+			mapGetS(t, t.mapRefStateS, ref.State),
+			sxpf.MakeString(ref.Value),
+		),
+	)
+}
+
+func (t *Transformer) GetMeta(m *meta.Meta, evalMeta encoder.EvalMetaFunc) *sxpf.List {
+	pairs := m.ComputedPairs()
+	objs := make([]sxpf.Object, 0, len(pairs))
+	for _, p := range pairs {
+		key := p.Key
+		ty := m.Type(key)
+		symType := mapGetS(t, t.mapMetaTypeS, ty)
+		var obj sxpf.Object
+		if ty.IsSet {
+			setList := meta.ListFromValue(p.Value)
+			setObjs := make([]sxpf.Object, len(setList))
+			for i, val := range setList {
+				setObjs[i] = sxpf.MakeString(val)
+			}
+			obj = sxpf.MakeList(setObjs...).Cons(t.zetSyms.SymList)
+		} else if ty == meta.TypeZettelmarkup {
+			is := evalMeta(p.Value)
+			obj = t.GetSz(&is)
+		} else {
+			obj = sxpf.MakeString(p.Value)
+		}
+		symKey := sxpf.MakeList(t.zetSyms.SymQuote, t.sf.MustMake(key))
+		objs = append(objs, sxpf.Nil().Cons(obj).Cons(symKey).Cons(symType))
+	}
+	return sxpf.MakeList(objs...).Cons(t.zetSyms.SymMeta)
+}
+
+func mapGetS[T comparable](t *Transformer, m map[T]*sxpf.Symbol, k T) *sxpf.Symbol {
+	if result, found := m[k]; found {
+		return result
+	}
+	return t.sf.MustMake(fmt.Sprintf("**%v:NOT-FOUND**", k))
+}
+
+func getBase64String(data []byte) sxpf.String {
+	var sb strings.Builder
+	encoder := base64.NewEncoder(base64.StdEncoding, &sb)
+	_, err := encoder.Write(data)
+	if err == nil {
+		err = encoder.Close()
+	}
+	if err == nil {
+		return sxpf.MakeString(sb.String())
+	}
+	return sxpf.MakeString("")
+}

Index: encoder/textenc/textenc.go
==================================================================
--- encoder/textenc/textenc.go
+++ encoder/textenc/textenc.go
@@ -14,12 +14,12 @@
 import (
 	"io"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	encoder.Register(api.EncoderText, func() encoder.Encoder { return Create() })
 }

Index: encoder/zmkenc/zmkenc.go
==================================================================
--- encoder/zmkenc/zmkenc.go
+++ encoder/zmkenc/zmkenc.go
@@ -17,14 +17,14 @@
 	"strings"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/c/attrs"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder"
 	"zettelstore.de/z/encoder/textenc"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	encoder.Register(api.EncoderZmk, func() encoder.Encoder { return Create() })
 }

Index: encoding/atom/atom.go
==================================================================
--- encoding/atom/atom.go
+++ encoding/atom/atom.go
@@ -15,17 +15,17 @@
 	"bytes"
 	"time"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoding"
 	"zettelstore.de/z/encoding/xml"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/query"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 const ContentType = "application/atom+xml"
 
 type Configuration struct {

Index: encoding/encoding.go
==================================================================
--- encoding/encoding.go
+++ encoding/encoding.go
@@ -13,13 +13,13 @@
 
 import (
 	"time"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // LastUpdated returns the formated time of the zettel which was updated at the latest time.
 func LastUpdated(ml []*meta.Meta, timeFormat string) string {
 	maxPublished := time.Date(1, time.January, 1, 0, 0, 0, 0, time.Local)

Index: encoding/rss/rss.go
==================================================================
--- encoding/rss/rss.go
+++ encoding/rss/rss.go
@@ -16,17 +16,17 @@
 	"context"
 	"time"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoding"
 	"zettelstore.de/z/encoding/xml"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/query"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 const ContentType = "application/rss+xml"
 
 type Configuration struct {

Index: evaluator/evaluator.go
==================================================================
--- evaluator/evaluator.go
+++ evaluator/evaluator.go
@@ -22,24 +22,24 @@
 	"zettelstore.de/c/api"
 	"zettelstore.de/c/attrs"
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/parser/cleaner"
 	"zettelstore.de/z/parser/draw"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Port contains all methods to retrieve zettel (or part of it) to evaluate a zettel.
 type Port interface {
 	GetMeta(context.Context, id.Zid) (*meta.Meta, error)
-	GetZettel(context.Context, id.Zid) (domain.Zettel, error)
+	GetZettel(context.Context, id.Zid) (zettel.Zettel, error)
 	SelectMeta(ctx context.Context, q *query.Query) ([]*meta.Meta, error)
 }
 
 // EvaluateZettel evaluates the given zettel in the given context, with the
 // given ports, and the given environment.
@@ -165,13 +165,13 @@
 }
 
 func (e *evaluator) evalVerbatimZettel(vn *ast.VerbatimNode) ast.BlockNode {
 	m := meta.New(id.Invalid)
 	m.Set(api.KeySyntax, getSyntax(vn.Attrs, meta.SyntaxText))
-	zettel := domain.Zettel{
+	zettel := zettel.Zettel{
 		Meta:    m,
-		Content: domain.NewContent(vn.Content),
+		Content: zettel.NewContent(vn.Content),
 	}
 	e.transcludeCount++
 	zn := e.evaluateEmbeddedZettel(zettel)
 	return &zn.Ast
 }
@@ -534,11 +534,11 @@
 	is := parser.ParseInlines(input.NewInput(content), syntax)
 	ast.Walk(e, &is)
 	return is
 }
 
-func (e *evaluator) evaluateEmbeddedZettel(zettel domain.Zettel) *ast.ZettelNode {
+func (e *evaluator) evaluateEmbeddedZettel(zettel zettel.Zettel) *ast.ZettelNode {
 	zn := parser.ParseZettel(e.ctx, zettel, zettel.Meta.GetDefault(api.KeySyntax, ""), e.rtConfig)
 	ast.Walk(e, &zn.Ast)
 	return zn
 }
 

Index: evaluator/list.go
==================================================================
--- evaluator/list.go
+++ evaluator/list.go
@@ -20,15 +20,15 @@
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/c/attrs"
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoding/atom"
 	"zettelstore.de/z/encoding/rss"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // QueryAction transforms a list of metadata according to query actions into a AST nested list.
 func QueryAction(ctx context.Context, q *query.Query, ml []*meta.Meta, rtConfig config.Config) ast.BlockNode {
 	ap := actionPara{

Index: evaluator/metadata.go
==================================================================
--- evaluator/metadata.go
+++ evaluator/metadata.go
@@ -10,11 +10,11 @@
 
 package evaluator
 
 import (
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func evaluateMetadata(m *meta.Meta) ast.BlockSlice {
 	descrlist := &ast.DescriptionListNode{}
 	for _, p := range m.Pairs() {

Index: go.mod
==================================================================
--- go.mod
+++ go.mod
@@ -1,17 +1,17 @@
 module zettelstore.de/z
 
 go 1.19
 
 require (
-	codeberg.org/t73fde/sxhtml v0.0.0-20230317170051-24321195e197
-	codeberg.org/t73fde/sxpf v0.0.0-20230319111333-7de220f3b475
+	codeberg.org/t73fde/sxhtml v0.0.0-20230527203734-55c7edf4d8d9
+	codeberg.org/t73fde/sxpf v0.0.0-20230524183624-37758f88d90e
 	github.com/fsnotify/fsnotify v1.6.0
 	github.com/pascaldekloe/jwt v1.12.0
 	github.com/yuin/goldmark v1.5.4
-	golang.org/x/crypto v0.7.0
-	golang.org/x/term v0.6.0
-	golang.org/x/text v0.8.0
-	zettelstore.de/c v0.11.0
+	golang.org/x/crypto v0.9.0
+	golang.org/x/term v0.8.0
+	golang.org/x/text v0.9.0
+	zettelstore.de/c v0.11.1-0.20230524183919-7e89180c6b97
 )
 
-require golang.org/x/sys v0.6.0 // indirect
+require golang.org/x/sys v0.8.0 // indirect

Index: go.sum
==================================================================
--- go.sum
+++ go.sum
@@ -1,21 +1,21 @@
-codeberg.org/t73fde/sxhtml v0.0.0-20230317170051-24321195e197 h1:6kX7TY25agLFlHNvByO1Jc3GrBA7mu7aOa8tCOniUew=
-codeberg.org/t73fde/sxhtml v0.0.0-20230317170051-24321195e197/go.mod h1:Dp3EwBSsE3TvdPw9QZ4Wm25ZragluVT2OayRFRiq6jk=
-codeberg.org/t73fde/sxpf v0.0.0-20230319111333-7de220f3b475 h1:0OTzV3FYY/Y7YsaVaSzF4Wd17pXzdH6DaSvMeqteJc4=
-codeberg.org/t73fde/sxpf v0.0.0-20230319111333-7de220f3b475/go.mod h1:iSbMygOmtRQYp8pryNKYzRuMibYDSR80smU2b6qm1bc=
+codeberg.org/t73fde/sxhtml v0.0.0-20230527203734-55c7edf4d8d9 h1:igzIvuvdkM3uuDFUFEwhQAyTpbDedpqIaOKLYTcJcwk=
+codeberg.org/t73fde/sxhtml v0.0.0-20230527203734-55c7edf4d8d9/go.mod h1:SXZmbDu/3buh48SxZSXp8j4CGyUS7T3M4Pn/2pG6oIs=
+codeberg.org/t73fde/sxpf v0.0.0-20230524183624-37758f88d90e h1:7AJv6wz7Pe/5vc9oqRdB6IVpJyrTBkSMA31yaIBn4CY=
+codeberg.org/t73fde/sxpf v0.0.0-20230524183624-37758f88d90e/go.mod h1:X+XmeukFGzykXmTnR1tyFmyB5kV7UdO8V1sX5gMwdRQ=
 github.com/fsnotify/fsnotify v1.6.0 h1:n+5WquG0fcWoWp6xPWfHdbskMCQaFnG6PfBrh1Ky4HY=
 github.com/fsnotify/fsnotify v1.6.0/go.mod h1:sl3t1tCWJFWoRz9R8WJCbQihKKwmorjAbSClcnxKAGw=
 github.com/pascaldekloe/jwt v1.12.0 h1:imQSkPOtAIBAXoKKjL9ZVJuF/rVqJ+ntiLGpLyeqMUQ=
 github.com/pascaldekloe/jwt v1.12.0/go.mod h1:LiIl7EwaglmH1hWThd/AmydNCnHf/mmfluBlNqHbk8U=
 github.com/yuin/goldmark v1.5.4 h1:2uY/xC0roWy8IBEGLgB1ywIoEJFGmRrX21YQcvGZzjU=
 github.com/yuin/goldmark v1.5.4/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
-golang.org/x/crypto v0.7.0 h1:AvwMYaRytfdeVt3u6mLaxYtErKYjxA2OXjJ1HHq6t3A=
-golang.org/x/crypto v0.7.0/go.mod h1:pYwdfH91IfpZVANVyUOhSIPZaFoJGxTFbZhFTx+dXZU=
+golang.org/x/crypto v0.9.0 h1:LF6fAI+IutBocDJ2OT0Q1g8plpYljMZ4+lty+dsqw3g=
+golang.org/x/crypto v0.9.0/go.mod h1:yrmDGqONDYtNj3tH8X9dzUun2m2lzPa9ngI6/RUPGR0=
 golang.org/x/sys v0.0.0-20220908164124-27713097b956/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.6.0 h1:MVltZSvRTcU2ljQOhs94SXPftV6DCNnZViHeQps87pQ=
-golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/term v0.6.0 h1:clScbb1cHjoCkyRbWwBEUZ5H/tIFu5TAXIqaZD0Gcjw=
-golang.org/x/term v0.6.0/go.mod h1:m6U89DPEgQRMq3DNkDClhWw02AUbt2daBVO4cn4Hv9U=
-golang.org/x/text v0.8.0 h1:57P1ETyNKtuIjB4SRd15iJxuhj8Gc416Y78H3qgMh68=
-golang.org/x/text v0.8.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
-zettelstore.de/c v0.11.0 h1:eD1og+5R2DC3po8JEYUKldONxo69uIKm0jmbNH+NfZI=
-zettelstore.de/c v0.11.0/go.mod h1:aYfHJ/ipU9BvYVBGVwOyfFjuGpf29Pf5Xn+pjcutR6E=
+golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
+golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.8.0 h1:n5xxQn2i3PC0yLAbjTpNT85q/Kgzcr2gIoX9OrJUols=
+golang.org/x/term v0.8.0/go.mod h1:xPskH00ivmX89bAKVGSKKtLOWNx2+17Eiy94tnKShWo=
+golang.org/x/text v0.9.0 h1:2sjJmO8cDvYveuX97RDLsxlyUxLl+GHoLxBiRdHllBE=
+golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
+zettelstore.de/c v0.11.1-0.20230524183919-7e89180c6b97 h1:4xu/maHyabllzLGMH2M8mkY0ZjaPrEbkBkLxCww666U=
+zettelstore.de/c v0.11.1-0.20230524183919-7e89180c6b97/go.mod h1:A9iEwwm0/OkKkJIMj5LtdXR7n1zIdwo6mqEsqgGzXxc=

Index: kernel/impl/auth.go
==================================================================
--- kernel/impl/auth.go
+++ kernel/impl/auth.go
@@ -13,13 +13,13 @@
 import (
 	"errors"
 	"sync"
 
 	"zettelstore.de/z/auth"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
+	"zettelstore.de/z/zettel/id"
 )
 
 type authService struct {
 	srvConfig
 	mxService     sync.RWMutex

Index: kernel/impl/cfg.go
==================================================================
--- kernel/impl/cfg.go
+++ kernel/impl/cfg.go
@@ -19,15 +19,15 @@
 	"sync"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type configService struct {
 	srvConfig
 	mxService sync.RWMutex

Index: kernel/impl/config.go
==================================================================
--- kernel/impl/config.go
+++ kernel/impl/config.go
@@ -17,13 +17,13 @@
 	"strconv"
 	"strings"
 	"sync"
 
 	"zettelstore.de/c/maps"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
+	"zettelstore.de/z/zettel/id"
 )
 
 type parseFunc func(string) (any, error)
 type configDescription struct {
 	text    string

Index: kernel/impl/core.go
==================================================================
--- kernel/impl/core.go
+++ kernel/impl/core.go
@@ -17,14 +17,14 @@
 	"runtime"
 	"sync"
 	"time"
 
 	"zettelstore.de/c/maps"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/id"
 )
 
 type coreService struct {
 	srvConfig
 	started bool

Index: kernel/impl/impl.go
==================================================================
--- kernel/impl/impl.go
+++ kernel/impl/impl.go
@@ -25,13 +25,13 @@
 	"strings"
 	"sync"
 	"syscall"
 	"time"
 
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
+	"zettelstore.de/z/zettel/id"
 )
 
 // myKernel is the main internal kernel.
 type myKernel struct {
 	logWriter *kernelLogWriter

Index: kernel/kernel.go
==================================================================
--- kernel/kernel.go
+++ kernel/kernel.go
@@ -17,13 +17,13 @@
 	"time"
 
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/id"
 )
 
 // Kernel is the main internal service.
 type Kernel interface {
 	// Setup sets the most basic data of a software: its name, its version,

Index: logger/logger.go
==================================================================
--- logger/logger.go
+++ logger/logger.go
@@ -16,11 +16,11 @@
 	"strconv"
 	"strings"
 	"sync/atomic"
 	"time"
 
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Level defines the possible log levels
 type Level uint8
 

Index: logger/message.go
==================================================================
--- logger/message.go
+++ logger/message.go
@@ -15,11 +15,11 @@
 	"net/http"
 	"strconv"
 	"sync"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
+	"zettelstore.de/z/zettel/id"
 )
 
 // Message presents a message to log.
 type Message struct {
 	logger *Logger

Index: parser/blob/blob.go
==================================================================
--- parser/blob/blob.go
+++ parser/blob/blob.go
@@ -11,13 +11,13 @@
 // Package blob provides a parser of binary data.
 package blob
 
 import (
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	parser.Register(&parser.Info{
 		Name:          meta.SyntaxGif,

Index: parser/draw/draw.go
==================================================================
--- parser/draw/draw.go
+++ parser/draw/draw.go
@@ -17,13 +17,13 @@
 import (
 	"strconv"
 
 	"zettelstore.de/c/attrs"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	parser.Register(&parser.Info{
 		Name:          meta.SyntaxDraw,

Index: parser/draw/draw_test.go
==================================================================
--- parser/draw/draw_test.go
+++ parser/draw/draw_test.go
@@ -12,17 +12,17 @@
 
 import (
 	"testing"
 
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func FuzzParseBlocks(f *testing.F) {
 	f.Fuzz(func(t *testing.T, src []byte) {
 		t.Parallel()
 		inp := input.NewInput(src)
 		parser.ParseBlocks(inp, nil, meta.SyntaxDraw, config.NoHTML)
 	})
 }

Index: parser/markdown/markdown.go
==================================================================
--- parser/markdown/markdown.go
+++ parser/markdown/markdown.go
@@ -21,14 +21,14 @@
 	gmAst "github.com/yuin/goldmark/ast"
 	gmText "github.com/yuin/goldmark/text"
 
 	"zettelstore.de/c/attrs"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder/textenc"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	parser.Register(&parser.Info{
 		Name:          meta.SyntaxMarkdown,

Index: parser/none/none.go
==================================================================
--- parser/none/none.go
+++ parser/none/none.go
@@ -11,13 +11,13 @@
 // Package none provides a none-parser, e.g. for zettel with just metadata.
 package none
 
 import (
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	parser.Register(&parser.Info{
 		Name:          meta.SyntaxNone,

Index: parser/parser.go
==================================================================
--- parser/parser.go
+++ parser/parser.go
@@ -17,14 +17,14 @@
 	"strings"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser/cleaner"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Info describes a single parser.
 //
 // Before ParseBlocks() or ParseInlines() is called, ensure the input stream to
@@ -149,11 +149,11 @@
 	}
 	return nil
 }
 
 // ParseZettel parses the zettel based on the syntax.
-func ParseZettel(ctx context.Context, zettel domain.Zettel, syntax string, rtConfig config.Config) *ast.ZettelNode {
+func ParseZettel(ctx context.Context, zettel zettel.Zettel, syntax string, rtConfig config.Config) *ast.ZettelNode {
 	m := zettel.Meta
 	inhMeta := m
 	if rtConfig != nil {
 		inhMeta = rtConfig.AddDefaultValues(ctx, inhMeta)
 	}

Index: parser/parser_test.go
==================================================================
--- parser/parser_test.go
+++ parser/parser_test.go
@@ -11,13 +11,13 @@
 package parser_test
 
 import (
 	"testing"
 
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/meta"
 
 	_ "zettelstore.de/z/parser/blob"       // Allow to use BLOB parser.
 	_ "zettelstore.de/z/parser/draw"       // Allow to use draw parser.
 	_ "zettelstore.de/z/parser/markdown"   // Allow to use markdown parser.
 	_ "zettelstore.de/z/parser/none"       // Allow to use none parser.
@@ -44,10 +44,11 @@
 		{meta.SyntaxMustache, false, true, false},
 		{meta.SyntaxNone, false, false, false},
 		{meta.SyntaxPlain, false, true, false},
 		{meta.SyntaxPNG, false, false, true},
 		{meta.SyntaxSVG, false, true, true},
+		{meta.SyntaxSxn, false, true, false},
 		{meta.SyntaxText, false, true, false},
 		{meta.SyntaxTxt, false, true, false},
 		{meta.SyntaxWebp, false, false, true},
 		{meta.SyntaxZmk, true, true, false},
 	}

Index: parser/plain/plain.go
==================================================================
--- parser/plain/plain.go
+++ parser/plain/plain.go
@@ -10,17 +10,21 @@
 
 // Package plain provides a parser for plain text data.
 package plain
 
 import (
+	"bytes"
 	"strings"
 
+	"codeberg.org/t73fde/sxpf/builtins/pprint"
+	"codeberg.org/t73fde/sxpf/builtins/quote"
+	"codeberg.org/t73fde/sxpf/reader"
 	"zettelstore.de/c/attrs"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	parser.Register(&parser.Info{
 		Name:          meta.SyntaxTxt,
@@ -56,10 +60,19 @@
 		IsTextFormat:  true,
 		IsImageFormat: true,
 		ParseBlocks:   parseSVGBlocks,
 		ParseInlines:  parseSVGInlines,
 	})
+	parser.Register(&parser.Info{
+		Name:          meta.SyntaxSxn,
+		AltNames:      []string{},
+		IsASTParser:   false,
+		IsTextFormat:  true,
+		IsImageFormat: false,
+		ParseBlocks:   parseSxnBlocks,
+		ParseInlines:  parseSxnInlines,
+	})
 	parser.Register(&parser.Info{
 		Name:          meta.SyntaxMustache,
 		AltNames:      []string{},
 		IsASTParser:   false,
 		IsTextFormat:  true,
@@ -128,5 +141,48 @@
 		return ""
 	}
 	// TODO: check proper end </svg>
 	return svgSrc
 }
+
+func parseSxnBlocks(inp *input.Input, _ *meta.Meta, syntax string) ast.BlockSlice {
+	rd := reader.MakeReader(bytes.NewReader(inp.Src))
+	sf := rd.SymbolFactory()
+	quote.InstallQuoteReader(rd, sf.MustMake("quote"), '\'')
+	quote.InstallQuasiQuoteReader(rd,
+		sf.MustMake("quasiquote"), '`',
+		sf.MustMake("unquote"), ',',
+		sf.MustMake("unquote-splicing"), '@')
+	objs, err := rd.ReadAll()
+	if err != nil {
+		return ast.BlockSlice{
+			&ast.VerbatimNode{
+				Kind:    ast.VerbatimProg,
+				Attrs:   attrs.Attributes{"": syntax},
+				Content: inp.ScanLineContent(),
+			},
+			ast.CreateParaNode(&ast.TextNode{
+				Text: err.Error(),
+			}),
+		}
+	}
+	result := make(ast.BlockSlice, len(objs))
+	for i, obj := range objs {
+		var buf bytes.Buffer
+		pprint.Print(&buf, obj)
+		result[i] = &ast.VerbatimNode{
+			Kind:    ast.VerbatimProg,
+			Attrs:   attrs.Attributes{"": syntax},
+			Content: buf.Bytes(),
+		}
+	}
+	return result
+}
+
+func parseSxnInlines(inp *input.Input, syntax string) ast.InlineSlice {
+	inp.SkipToEOL()
+	return ast.InlineSlice{&ast.LiteralNode{
+		Kind:    ast.LiteralProg,
+		Attrs:   attrs.Attributes{"": syntax},
+		Content: append([]byte(nil), inp.Src[0:inp.Pos]...),
+	}}
+}

Index: parser/zettelmark/inline.go
==================================================================
--- parser/zettelmark/inline.go
+++ parser/zettelmark/inline.go
@@ -15,12 +15,12 @@
 	"fmt"
 	"strings"
 
 	"zettelstore.de/c/attrs"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // parseInlineSlice parses a sequence of Inlines until EOS.
 func (cp *zmkP) parseInlineSlice() (ins ast.InlineSlice) {
 	inp := cp.inp

Index: parser/zettelmark/zettelmark.go
==================================================================
--- parser/zettelmark/zettelmark.go
+++ parser/zettelmark/zettelmark.go
@@ -15,13 +15,13 @@
 	"strings"
 	"unicode"
 
 	"zettelstore.de/c/attrs"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func init() {
 	parser.Register(&parser.Info{
 		Name:          meta.SyntaxZmk,

Index: parser/zettelmark/zettelmark_fuzz_test.go
==================================================================
--- parser/zettelmark/zettelmark_fuzz_test.go
+++ parser/zettelmark/zettelmark_fuzz_test.go
@@ -12,17 +12,17 @@
 
 import (
 	"testing"
 
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func FuzzParseBlocks(f *testing.F) {
 	f.Fuzz(func(t *testing.T, src []byte) {
 		t.Parallel()
 		inp := input.NewInput(src)
 		parser.ParseBlocks(inp, nil, meta.SyntaxZmk, config.NoHTML)
 	})
 }

Index: parser/zettelmark/zettelmark_test.go
==================================================================
--- parser/zettelmark/zettelmark_test.go
+++ parser/zettelmark/zettelmark_test.go
@@ -17,13 +17,13 @@
 	"testing"
 
 	"zettelstore.de/c/attrs"
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type TestCase struct{ source, want string }
 type TestCases []TestCase
 

ADDED   query/compiled.go
Index: query/compiled.go
==================================================================
--- query/compiled.go
+++ query/compiled.go
@@ -0,0 +1,185 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2023-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package query
+
+import (
+	"math/rand"
+	"sort"
+
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
+)
+
+// Compiled is a compiled query, to be used in a Box
+type Compiled struct {
+	hasQuery bool
+	seed     int
+	pick     int
+	order    []sortOrder
+	offset   int // <= 0: no offset
+	limit    int // <= 0: no limit
+
+	contextMeta []*meta.Meta
+	PreMatch    MetaMatchFunc // Precondition for Match and Retrieve
+	Terms       []CompiledTerm
+}
+
+// MetaMatchFunc is a function determine whethe some metadata should be selected or not.
+type MetaMatchFunc func(*meta.Meta) bool
+
+func matchAlways(*meta.Meta) bool { return true }
+func matchNever(*meta.Meta) bool  { return false }
+
+// CompiledTerm is the preprocessed sequence of conjugated search terms.
+type CompiledTerm struct {
+	Match    MetaMatchFunc     // Match on metadata
+	Retrieve RetrievePredicate // Retrieve from full-text search
+}
+
+// RetrievePredicate returns true, if the given Zid is contained in the (full-text) search.
+type RetrievePredicate func(id.Zid) bool
+
+func (c *Compiled) isDeterministic() bool { return c.seed > 0 }
+
+// Result returns a result of the compiled search, that is achievable without iterating through a box.
+func (c *Compiled) Result() []*meta.Meta {
+	if len(c.contextMeta) == 0 {
+		// nil -> no context
+		// empty slice -> nothing found
+		return c.contextMeta
+	}
+	result := make([]*meta.Meta, 0, len(c.contextMeta))
+	for _, m := range c.contextMeta {
+		for _, term := range c.Terms {
+			if term.Match(m) {
+				result = append(result, m)
+				break
+			}
+		}
+	}
+	result = c.pickElements(result)
+	result = c.sortElements(result)
+	result = c.offsetElements(result)
+	return limitElements(result, c.limit)
+}
+
+// AfterSearch applies all terms to the metadata list that was searched.
+//
+// This includes sorting, offset, limit, and picking.
+func (c *Compiled) AfterSearch(metaList []*meta.Meta) []*meta.Meta {
+	if len(metaList) == 0 {
+		return metaList
+	}
+
+	if !c.hasQuery {
+		return sortMetaByZid(metaList)
+	}
+
+	if c.isDeterministic() {
+		// We need to sort to make it deterministic
+		if len(c.order) == 0 || c.order[0].isRandom() {
+			metaList = sortMetaByZid(metaList)
+		} else {
+			sort.Slice(metaList, createSortFunc(c.order, metaList))
+		}
+	}
+	metaList = c.pickElements(metaList)
+	if c.isDeterministic() {
+		if len(c.order) > 0 && c.order[0].isRandom() {
+			metaList = c.sortRandomly(metaList)
+		}
+	} else {
+		metaList = c.sortElements(metaList)
+	}
+	metaList = c.offsetElements(metaList)
+	return limitElements(metaList, c.limit)
+}
+
+func (c *Compiled) sortElements(metaList []*meta.Meta) []*meta.Meta {
+	if len(c.order) > 0 {
+		if c.order[0].isRandom() {
+			metaList = c.sortRandomly(metaList)
+		} else {
+			sort.Slice(metaList, createSortFunc(c.order, metaList))
+		}
+	}
+	return metaList
+}
+
+func (c *Compiled) offsetElements(metaList []*meta.Meta) []*meta.Meta {
+	if c.offset == 0 {
+		return metaList
+	}
+	if c.offset > len(metaList) {
+		return nil
+	}
+	return metaList[c.offset:]
+}
+
+func (c *Compiled) pickElements(metaList []*meta.Meta) []*meta.Meta {
+	count := c.pick
+	if count <= 0 || count >= len(metaList) {
+		return metaList
+	}
+	if limit := c.limit; limit > 0 && limit < count {
+		count = limit
+		c.limit = 0
+	}
+
+	order := make([]int, len(metaList))
+	for i := 0; i < len(metaList); i++ {
+		order[i] = i
+	}
+	rnd := c.newRandom()
+	picked := make([]int, count)
+	for i := 0; i < count; i++ {
+		last := len(order) - i
+		n := rnd.Intn(last)
+		picked[i] = order[n]
+		order[n] = order[last-1]
+	}
+	order = nil
+	sort.Ints(picked)
+	result := make([]*meta.Meta, count)
+	for i, p := range picked {
+		result[i] = metaList[p]
+	}
+	return result
+}
+
+func (c *Compiled) sortRandomly(metaList []*meta.Meta) []*meta.Meta {
+	rnd := c.newRandom()
+	rnd.Shuffle(
+		len(metaList),
+		func(i, j int) { metaList[i], metaList[j] = metaList[j], metaList[i] },
+	)
+	return metaList
+}
+
+func (c *Compiled) newRandom() *rand.Rand {
+	seed := c.seed
+	if seed <= 0 {
+		seed = rand.Intn(10000) + 10001
+	}
+	return rand.New(rand.NewSource(int64(seed)))
+}
+
+func limitElements(metaList []*meta.Meta, limit int) []*meta.Meta {
+	if limit > 0 && limit < len(metaList) {
+		return metaList[:limit]
+	}
+	return metaList
+}
+
+func sortMetaByZid(metaList []*meta.Meta) []*meta.Meta {
+	sort.Slice(metaList, func(i, j int) bool { return metaList[i].Zid > metaList[j].Zid })
+	return metaList
+}

ADDED   query/context.go
Index: query/context.go
==================================================================
--- query/context.go
+++ query/context.go
@@ -0,0 +1,287 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2023-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package query
+
+import (
+	"context"
+
+	"zettelstore.de/c/api"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
+)
+
+type contextDirection uint8
+
+const (
+	_ contextDirection = iota
+	dirForward
+	dirBackward
+	dirBoth
+)
+
+func (q *Query) getContext(ctx context.Context, preMatch MetaMatchFunc, getMeta GetMetaFunc, selectMeta SelectMetaFunc) ([]*meta.Meta, error) {
+	if !q.zid.IsValid() {
+		return nil, nil
+	}
+
+	start, err := getMeta(ctx, q.zid)
+	if err != nil {
+		return nil, err
+	}
+	if !preMatch(start) {
+		return []*meta.Meta{}, nil
+	}
+	maxCost := q.maxCost
+	if maxCost <= 0 {
+		maxCost = 17
+	}
+	maxCount := q.maxCount
+	if maxCount <= 0 {
+		maxCount = 200
+	}
+	tasks := newQueue(start, maxCost, maxCount, preMatch, getMeta, selectMeta)
+	isBackward := q.dir == dirBoth || q.dir == dirBackward
+	isForward := q.dir == dirBoth || q.dir == dirForward
+	result := []*meta.Meta{}
+	for {
+		m, cost := tasks.next()
+		if m == nil {
+			break
+		}
+		result = append(result, m)
+
+		for _, p := range m.ComputedPairsRest() {
+			tasks.addPair(ctx, p.Key, p.Value, cost, isBackward, isForward)
+		}
+		if tags, found := m.GetList(api.KeyTags); found {
+			for _, tag := range tags {
+				tasks.addSameTag(ctx, tag, cost)
+			}
+		}
+	}
+	return result, nil
+}
+
+type ztlCtxTask struct {
+	next *ztlCtxTask
+	prev *ztlCtxTask
+	meta *meta.Meta
+	cost int
+}
+
+type contextQueue struct {
+	preMatch   MetaMatchFunc
+	getMeta    GetMetaFunc
+	selectMeta SelectMetaFunc
+	seen       id.Set
+	first      *ztlCtxTask
+	last       *ztlCtxTask
+	maxCost    int
+	limit      int
+	tagCost    map[string][]*meta.Meta
+}
+
+func newQueue(m *meta.Meta, maxCost, limit int, preMatch MetaMatchFunc, getMeta GetMetaFunc, selectMeta SelectMetaFunc) *contextQueue {
+	task := &ztlCtxTask{
+		next: nil,
+		prev: nil,
+		meta: m,
+		cost: 1,
+	}
+	result := &contextQueue{
+		preMatch:   preMatch,
+		getMeta:    getMeta,
+		selectMeta: selectMeta,
+		seen:       id.NewSet(),
+		first:      task,
+		last:       task,
+		maxCost:    maxCost,
+		limit:      limit,
+		tagCost:    make(map[string][]*meta.Meta, 1024),
+	}
+	return result
+}
+
+func (zc *contextQueue) addPair(ctx context.Context, key, value string, curCost int, isBackward, isForward bool) {
+	if key == api.KeyBack {
+		return
+	}
+	newCost := curCost + contextCost(key)
+	if key == api.KeyBackward {
+		if isBackward {
+			zc.addIDSet(ctx, newCost, value)
+		}
+		return
+	}
+	if key == api.KeyForward {
+		if isForward {
+			zc.addIDSet(ctx, newCost, value)
+		}
+		return
+	}
+	hasInverse := meta.Inverse(key) != ""
+	if (!hasInverse || !isBackward) && (hasInverse || !isForward) {
+		return
+	}
+	if t := meta.Type(key); t == meta.TypeID {
+		zc.addID(ctx, newCost, value)
+	} else if t == meta.TypeIDSet {
+		zc.addIDSet(ctx, newCost, value)
+	}
+}
+
+func contextCost(key string) int {
+	switch key {
+	case api.KeyFolge, api.KeyPrecursor:
+		return 1
+	case api.KeySuccessors, api.KeyPredecessor,
+		api.KeySubordinates, api.KeySuperior:
+		return 2
+	}
+	return 3
+}
+
+func (zc *contextQueue) addID(ctx context.Context, newCost int, value string) {
+	if zc.costMaxed(newCost) {
+		return
+	}
+
+	zid, err := id.Parse(value)
+	if err != nil {
+		return
+	}
+	m, err := zc.getMeta(ctx, zid)
+	if err != nil {
+		return
+	}
+	if zc.preMatch(m) {
+		zc.addMeta(m, newCost)
+	}
+}
+func (zc *contextQueue) addMeta(m *meta.Meta, newCost int) {
+	task := &ztlCtxTask{next: nil, prev: nil, meta: m, cost: newCost}
+	if zc.first == nil {
+		zc.first = task
+		zc.last = task
+		return
+	}
+
+	// Search backward for a task t with at most the same cost
+	for t := zc.last; t != nil; t = t.prev {
+		if t.cost <= task.cost {
+			// Found!
+			if t.next != nil {
+				t.next.prev = task
+			}
+			task.next = t.next
+			t.next = task
+			task.prev = t
+			if task.next == nil {
+				zc.last = task
+			}
+			return
+		}
+	}
+
+	// We have not found a task, therefore the new task is the first one
+	task.next = zc.first
+	zc.first.prev = task
+	zc.first = task
+}
+
+func (zc *contextQueue) costMaxed(newCost int) bool {
+	return (zc.maxCost > 0 && newCost > zc.maxCost) || zc.hasLimit()
+}
+
+func (zc *contextQueue) addIDSet(ctx context.Context, newCost int, value string) {
+	elems := meta.ListFromValue(value)
+	refCost := referenceCost(newCost, len(elems))
+	for _, val := range elems {
+		zc.addID(ctx, refCost, val)
+	}
+}
+
+func referenceCost(baseCost int, numReferences int) int {
+	if numReferences < 5 {
+		return baseCost + 1
+	}
+	if numReferences < 9 {
+		return baseCost * 2
+	}
+	if numReferences < 17 {
+		return baseCost * 3
+	}
+	if numReferences < 33 {
+		return baseCost * 4
+	}
+	if numReferences < 65 {
+		return baseCost * 5
+	}
+	return baseCost * numReferences / 8
+}
+
+func (zc *contextQueue) addSameTag(ctx context.Context, tag string, baseCost int) {
+	tagMetas, found := zc.tagCost[tag]
+	if !found {
+		q := Parse(api.KeyTags + api.SearchOperatorHas + tag + " ORDER REVERSE " + api.KeyID)
+		ml, err := zc.selectMeta(ctx, q)
+		if err != nil {
+			return
+		}
+		tagMetas = ml
+		zc.tagCost[tag] = ml
+	}
+	cost := tagCost(baseCost, len(tagMetas))
+	if zc.costMaxed(cost) {
+		return
+	}
+	for _, m := range tagMetas {
+		if zc.preMatch(m) { // selectMeta will not check preMatch
+			zc.addMeta(m, cost)
+		}
+	}
+}
+
+func tagCost(baseCost, numTags int) int {
+	if numTags < 8 {
+		return baseCost + numTags/2
+	}
+	return (baseCost + 2) * (numTags / 4)
+}
+
+func (zc *contextQueue) next() (*meta.Meta, int) {
+	if zc.hasLimit() {
+		return nil, -1
+	}
+	for zc.first != nil {
+		task := zc.first
+		zc.first = task.next
+		if zc.first == nil {
+			zc.last = nil
+		} else {
+			zc.first.prev = nil
+		}
+		m := task.meta
+		zid := m.Zid
+		_, found := zc.seen[zid]
+		if found {
+			continue
+		}
+		zc.seen.Zid(zid)
+		return m, task.cost
+	}
+	return nil, -1
+}
+
+func (zc *contextQueue) hasLimit() bool {
+	limit := zc.limit
+	return limit > 0 && len(zc.seen) > limit
+}

Index: query/parser.go
==================================================================
--- query/parser.go
+++ query/parser.go
@@ -11,12 +11,14 @@
 package query
 
 import (
 	"strconv"
 
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/c/api"
 	"zettelstore.de/z/input"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Parse the query specification and return a Query object.
 func Parse(spec string) (q *Query) { return q.Parse(spec) }
 
@@ -55,25 +57,32 @@
 
 const (
 	actionSeparatorChar      = '|'
 	existOperatorChar        = '?'
 	searchOperatorNotChar    = '!'
+	searchOperatorEqualChar  = '='
 	searchOperatorHasChar    = ':'
 	searchOperatorPrefixChar = '>'
 	searchOperatorSuffixChar = '<'
 	searchOperatorMatchChar  = '~'
 
-	kwLimit   = "LIMIT"
-	kwOffset  = "OFFSET"
-	kwOr      = "OR"
-	kwOrder   = "ORDER"
-	kwPick    = "PICK"
-	kwRandom  = "RANDOM"
-	kwReverse = "REVERSE"
+	kwBackward = "BACKWARD"
+	kwContext  = api.ContextDirective
+	kwCost     = "COST"
+	kwForward  = "FORWARD"
+	kwMax      = "MAX"
+	kwLimit    = "LIMIT"
+	kwOffset   = "OFFSET"
+	kwOr       = "OR"
+	kwOrder    = "ORDER"
+	kwPick     = "PICK"
+	kwRandom   = "RANDOM"
+	kwReverse  = "REVERSE"
 )
 
 func (ps *parserState) parse(q *Query) *Query {
+	q = ps.parseContext(q)
 	inp := ps.inp
 	for {
 		ps.skipSpace()
 		if ps.mustStop() {
 			break
@@ -87,11 +96,11 @@
 			continue
 		}
 		inp.SetPos(pos)
 		if ps.acceptSingleKw(kwRandom) {
 			q = createIfNeeded(q)
-			if len(q.order) == 0 && q.pick <= 0 {
+			if len(q.order) == 0 {
 				q.order = []sortOrder{{"", false}}
 			}
 			continue
 		}
 		inp.SetPos(pos)
@@ -130,22 +139,96 @@
 		q = ps.parseText(q)
 	}
 	return q
 }
 
+func (ps *parserState) parseContext(q *Query) *Query {
+	inp := ps.inp
+	ps.skipSpace()
+	if ps.mustStop() {
+		return q
+	}
+	pos := inp.Pos
+	if !ps.acceptSingleKw(kwContext) {
+		inp.SetPos(pos)
+		return q
+	}
+	ps.skipSpace()
+	if ps.mustStop() {
+		inp.SetPos(pos)
+		return q
+	}
+	zid, ok := ps.scanZid()
+	if !ok {
+		inp.SetPos(pos)
+		return q
+	}
+
+	q = createIfNeeded(q)
+	q.zid = zid
+	q.dir = dirBoth
+
+	for {
+		ps.skipSpace()
+		if ps.mustStop() {
+			return q
+		}
+		pos = inp.Pos
+		if ps.acceptSingleKw(kwBackward) {
+			q.dir = dirBackward
+			continue
+		}
+		inp.SetPos(pos)
+		if ps.acceptSingleKw(kwForward) {
+			q.dir = dirForward
+			continue
+		}
+		inp.SetPos(pos)
+		if ps.acceptKwArgs(kwCost) {
+			if ps.parseCost(q) {
+				continue
+			}
+		}
+		inp.SetPos(pos)
+		if ps.acceptKwArgs(kwMax) {
+			if ps.parseCount(q) {
+				continue
+			}
+		}
+		inp.SetPos(pos)
+		return q
+	}
+}
+func (ps *parserState) parseCost(q *Query) bool {
+	num, ok := ps.scanPosInt()
+	if !ok {
+		return false
+	}
+	if q.maxCost == 0 || q.maxCost >= num {
+		q.maxCost = num
+	}
+	return true
+}
+func (ps *parserState) parseCount(q *Query) bool {
+	num, ok := ps.scanPosInt()
+	if !ok {
+		return false
+	}
+	if q.maxCount == 0 || q.maxCount >= num {
+		q.maxCount = num
+	}
+	return true
+}
 func (ps *parserState) parsePick(q *Query) (*Query, bool) {
 	num, ok := ps.scanPosInt()
 	if !ok {
 		return q, false
 	}
 	q = createIfNeeded(q)
 	if q.pick == 0 || q.pick >= num {
 		q.pick = num
 	}
-	if len(q.order) == 1 && q.order[0].isRandom() {
-		q.order = nil
-	}
 	return q, true
 }
 
 func (ps *parserState) parseOrder(q *Query) (*Query, bool) {
 	reverse := false
@@ -263,11 +346,12 @@
 	allowKey := !hasOp
 
 	for !ps.isSpace() && !isActionSep(inp.Ch) && !ps.mustStop() {
 		if allowKey {
 			switch inp.Ch {
-			case searchOperatorNotChar, existOperatorChar, searchOperatorHasChar,
+			case searchOperatorNotChar, existOperatorChar,
+				searchOperatorEqualChar, searchOperatorHasChar,
 				searchOperatorPrefixChar, searchOperatorSuffixChar, searchOperatorMatchChar:
 				allowKey = false
 				if key := inp.Src[pos:inp.Pos]; meta.KeyIsValid(string(key)) {
 					return nil, key
 				}
@@ -286,19 +370,10 @@
 	}
 	return inp.Src[pos:inp.Pos]
 }
 
 func (ps *parserState) scanPosInt() (int, bool) {
-	inp := ps.inp
-	ch := inp.Ch
-	if ch == '0' {
-		ch = inp.Next()
-		if isSpace(ch) || isActionSep(inp.Ch) || ps.mustStop() {
-			return 0, true
-		}
-		return 0, false
-	}
 	word := ps.scanWord()
 	if len(word) == 0 {
 		return 0, false
 	}
 	uval, err := strconv.ParseUint(string(word), 10, 63)
@@ -305,10 +380,23 @@
 	if err != nil {
 		return 0, false
 	}
 	return int(uval), true
 }
+
+func (ps *parserState) scanZid() (id.Zid, bool) {
+	word := ps.scanWord()
+	if len(word) == 0 {
+		return id.Invalid, false
+	}
+	uval, err := id.ParseUint(string(word))
+	if err != nil {
+		return id.Invalid, false
+	}
+	zid := id.Zid(uval)
+	return zid, zid.IsValid()
+}
 
 func (ps *parserState) scanSearchOp() (compareOp, bool) {
 	inp := ps.inp
 	ch := inp.Ch
 	negate := false
@@ -319,10 +407,13 @@
 	op := cmpUnknown
 	switch ch {
 	case existOperatorChar:
 		inp.Next()
 		op = cmpExist
+	case searchOperatorEqualChar:
+		inp.Next()
+		op = cmpEqual
 	case searchOperatorHasChar:
 		inp.Next()
 		op = cmpHas
 	case searchOperatorSuffixChar:
 		inp.Next()

Index: query/parser_test.go
==================================================================
--- query/parser_test.go
+++ query/parser_test.go
@@ -20,44 +20,58 @@
 	t.Parallel()
 	testcases := []struct {
 		spec string
 		exp  string
 	}{
+		{"CONTEXT", "CONTEXT"}, {"CONTEXT 0", "CONTEXT 0"}, {"CONTEXT a", "CONTEXT a"},
+		{"CONTEXT 1", "CONTEXT 00000000000001"},
+		{"CONTEXT 00000000000001", "CONTEXT 00000000000001"},
+		{"CONTEXT 100000000000001", "CONTEXT 100000000000001"},
+		{"CONTEXT 1 BACKWARD", "CONTEXT 00000000000001 BACKWARD"},
+		{"CONTEXT 1 FORWARD", "CONTEXT 00000000000001 FORWARD"},
+		{"CONTEXT 1 COST 3", "CONTEXT 00000000000001 COST 3"}, {"CONTEXT 1 COST x", "CONTEXT 00000000000001 COST x"},
+		{"CONTEXT 1 MAX 5", "CONTEXT 00000000000001 MAX 5"}, {"CONTEXT 1 MAX y", "CONTEXT 00000000000001 MAX y"},
+		{"CONTEXT 1 MAX 5 COST 7", "CONTEXT 00000000000001 COST 7 MAX 5"},
+		{"CONTEXT 1 |  N", "CONTEXT 00000000000001 | N"},
 		{"?", "?"}, {"!?", "!?"}, {"?a", "?a"}, {"!?a", "!?a"},
 		{"key?", "key?"}, {"key!?", "key!?"},
 		{"b key?", "key? b"}, {"b key!?", "key!? b"},
 		{"key?a", "key?a"}, {"key!?a", "key!?a"},
 		{"", ""}, {"!", ""}, {":", ""}, {"!:", ""}, {">", ""}, {"!>", ""}, {"<", ""}, {"!<", ""}, {"~", ""}, {"!~", ""},
 		{`a`, `a`}, {`!a`, `!a`},
+		{`=a`, `=a`}, {`!=a`, `!=a`},
 		{`:a`, `:a`}, {`!:a`, `!:a`},
 		{`>a`, `>a`}, {`!>a`, `!>a`},
 		{`<a`, `<a`}, {`!<a`, `!<a`},
 		{`~a`, `a`}, {`!~a`, `!a`},
+		{`key=`, `key=`}, {`key!=`, `key!=`},
 		{`key:`, `key:`}, {`key!:`, `key!:`},
 		{`key>`, `key>`}, {`key!>`, `key!>`},
 		{`key<`, `key<`}, {`key!<`, `key!<`},
 		{`key~`, `key~`}, {`key!~`, `key!~`},
+		{`key=a`, `key=a`}, {`key!=a`, `key!=a`},
 		{`key:a`, `key:a`}, {`key!:a`, `key!:a`},
 		{`key>a`, `key>a`}, {`key!>a`, `key!>a`},
 		{`key<a`, `key<a`}, {`key!<a`, `key!<a`},
 		{`key~a`, `key~a`}, {`key!~a`, `key!~a`},
 		{`key1:a key2:b`, `key1:a key2:b`},
 		{`key1: key2:b`, `key1: key2:b`},
 		{"word key:a", "key:a word"},
-		{`PICK 3`, `PICK 3`}, {`PICK 9 PICK 11`, `PICK 9`}, {`PICK 5 RANDOM`, `PICK 5`}, {`RANDOM PICK 7`, `PICK 7`},
+		{`PICK 3`, `PICK 3`}, {`PICK 9 PICK 11`, `PICK 9`},
+		{"PICK a", "PICK a"},
 		{`RANDOM`, `RANDOM`}, {`RANDOM a`, `a RANDOM`}, {`a RANDOM`, `a RANDOM`},
 		{`RANDOM RANDOM a`, `a RANDOM`},
 		{`RANDOMRANDOM a`, `RANDOMRANDOM a`}, {`a RANDOMRANDOM`, `a RANDOMRANDOM`},
 		{`ORDER`, `ORDER`}, {"ORDER a b", "b ORDER a"}, {"a ORDER", "a ORDER"}, {"ORDER %", "ORDER %"},
 		{"ORDER a %", "% ORDER a"},
 		{"ORDER REVERSE", "ORDER REVERSE"}, {"ORDER REVERSE a b", "b ORDER REVERSE a"},
 		{"a RANDOM ORDER b", "a ORDER b"}, {"a ORDER b RANDOM", "a ORDER b"},
 		{"OFFSET", "OFFSET"}, {"OFFSET a", "OFFSET a"}, {"OFFSET 10 a", "a OFFSET 10"},
-		{"OFFSET 01 a", "OFFSET 01 a"}, {"OFFSET 0 a", "a"}, {"a OFFSET 0", "a"},
+		{"OFFSET 01 a", "a OFFSET 1"}, {"OFFSET 0 a", "a"}, {"a OFFSET 0", "a"},
 		{"OFFSET 4 OFFSET 8", "OFFSET 8"}, {"OFFSET 8 OFFSET 4", "OFFSET 8"},
 		{"LIMIT", "LIMIT"}, {"LIMIT a", "LIMIT a"}, {"LIMIT 10 a", "a LIMIT 10"},
-		{"LIMIT 01 a", "LIMIT 01 a"}, {"LIMIT 0 a", "a"}, {"a LIMIT 0", "a"},
+		{"LIMIT 01 a", "a LIMIT 1"}, {"LIMIT 0 a", "a"}, {"a LIMIT 0", "a"},
 		{"LIMIT 4 LIMIT 8", "LIMIT 4"}, {"LIMIT 8 LIMIT 4", "LIMIT 4"},
 		{"OR", ""}, {"OR OR", ""}, {"a OR", "a"}, {"OR b", "b"}, {"OR a OR", "a"},
 		{"a OR b", "a OR b"},
 		{"|", ""}, {" | RANDOM", "| RANDOM"}, {"| RANDOM", "| RANDOM"}, {"a|a b ", "a | a b"},
 	}

Index: query/print.go
==================================================================
--- query/print.go
+++ query/print.go
@@ -20,10 +20,12 @@
 )
 
 var op2string = map[compareOp]string{
 	cmpExist:    api.ExistOperator,
 	cmpNotExist: api.ExistNotOperator,
+	cmpEqual:    api.SearchOperatorEqual,
+	cmpNotEqual: api.SearchOperatorNotEqual,
 	cmpHas:      api.SearchOperatorHas,
 	cmpHasNot:   api.SearchOperatorHasNot,
 	cmpPrefix:   api.SearchOperatorPrefix,
 	cmpNoPrefix: api.SearchOperatorNoPrefix,
 	cmpSuffix:   api.SearchOperatorSuffix,
@@ -42,10 +44,11 @@
 func (q *Query) Print(w io.Writer) {
 	if q == nil {
 		return
 	}
 	env := printEnv{w: w}
+	env.printContext(q)
 	for i, term := range q.terms {
 		if i > 0 {
 			env.writeString(" OR")
 		}
 		for _, name := range maps.Keys(term.keys) {
@@ -89,10 +92,30 @@
 	pe.space = true
 }
 func (pe *printEnv) write(ch byte)        { pe.w.Write([]byte{ch}) }
 func (pe *printEnv) writeString(s string) { io.WriteString(pe.w, s) }
 
+func (pe *printEnv) printContext(q *Query) {
+	if zid := q.zid; zid.IsValid() {
+		pe.writeString(kwContext)
+		pe.space = true
+		pe.printSpace()
+		pe.writeString(zid.String())
+		switch q.dir {
+		case dirBackward:
+			pe.printSpace()
+			pe.writeString(kwBackward)
+		case dirForward:
+			pe.printSpace()
+			pe.writeString(kwForward)
+		}
+		pe.printPosInt(kwCost, q.maxCost)
+		pe.printPosInt(kwMax, q.maxCount)
+		// pe.writeString("!")
+	}
+
+}
 func (pe *printEnv) printExprValues(key string, values []expValue) {
 	for _, val := range values {
 		pe.printSpace()
 		pe.writeString(key)
 		switch op := val.op; op {
@@ -133,10 +156,11 @@
 func (q *Query) PrintHuman(w io.Writer) {
 	if q == nil {
 		return
 	}
 	env := printEnv{w: w}
+	env.printContext(q)
 	for i, term := range q.terms {
 		if i > 0 {
 			env.writeString(" OR ")
 			env.space = false
 		}
@@ -189,10 +213,14 @@
 	for j, val := range values {
 		if j > 0 {
 			pe.writeString(" AND")
 		}
 		switch val.op {
+		case cmpEqual:
+			pe.writeString(" EQUALS ")
+		case cmpNotEqual:
+			pe.writeString(" EQUALS NOT ")
 		case cmpHas:
 			pe.writeString(" HAS ")
 		case cmpHasNot:
 			pe.writeString(" HAS NOT ")
 		case cmpPrefix:
@@ -222,12 +250,10 @@
 	for _, o := range order {
 		if o.isRandom() {
 			pe.printSpace()
 			pe.writeString(kwRandom)
 			continue
-		} else if o.key == api.KeyID && o.descending {
-			continue
 		}
 		pe.printSpace()
 		pe.writeString(kwOrder)
 		if o.descending {
 			pe.printSpace()

Index: query/query.go
==================================================================
--- query/query.go
+++ query/query.go
@@ -10,15 +10,15 @@
 
 // Package query provides a query for zettel.
 package query
 
 import (
+	"context"
 	"math/rand"
-	"sort"
 
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Searcher is used to select zettel identifier based on search criteria.
 type Searcher interface {
 	// Select all zettel that contains the given exact word.
@@ -38,10 +38,16 @@
 	SearchContains(s string) id.Set
 }
 
 // Query specifies a mechanism for querying zettel.
 type Query struct {
+	// Fields for context. Only valid if zid.IsValid().
+	zid      id.Zid
+	dir      contextDirection
+	maxCost  int
+	maxCount int
+
 	// Fields to be used for selecting
 	preMatch MetaMatchFunc // Match that must be true
 	terms    []conjTerms
 
 	// Allow to create predictable randomness
@@ -56,31 +62,10 @@
 
 	// Execute specification
 	actions []string
 }
 
-// Compiled is a compiled query, to be used in a Box
-type Compiled struct {
-	PreMatch MetaMatchFunc // Precondition for Match and Retrieve
-	Terms    []CompiledTerm
-}
-
-// MetaMatchFunc is a function determine whethe some metadata should be selected or not.
-type MetaMatchFunc func(*meta.Meta) bool
-
-func matchAlways(*meta.Meta) bool { return true }
-func matchNever(*meta.Meta) bool  { return false }
-
-// CompiledTerm is the preprocessed sequence of conjugated search terms.
-type CompiledTerm struct {
-	Match    MetaMatchFunc     // Match on metadata
-	Retrieve RetrievePredicate // Retrieve from full-text search
-}
-
-// RetrievePredicate returns true, if the given Zid is contained in the (full-text) search.
-type RetrievePredicate func(id.Zid) bool
-
 type keyExistMap map[string]compareOp
 type expMetaValues map[string][]expValue
 
 type conjTerms struct {
 	keys   keyExistMap
@@ -126,10 +111,17 @@
 func (q *Query) Clone() *Query {
 	if q == nil {
 		return nil
 	}
 	c := new(Query)
+	c.zid = q.zid
+	if q.zid.IsValid() {
+		c.dir = q.dir
+		c.maxCost = q.maxCost
+		c.maxCount = q.maxCount
+	}
+
 	c.preMatch = q.preMatch
 	c.terms = make([]conjTerms, len(q.terms))
 	for i, term := range q.terms {
 		if len(term.keys) > 0 {
 			c.terms[i].keys = make(keyExistMap, len(term.keys))
@@ -162,10 +154,12 @@
 
 const (
 	cmpUnknown compareOp = iota
 	cmpExist
 	cmpNotExist
+	cmpEqual
+	cmpNotEqual
 	cmpHas
 	cmpHasNot
 	cmpPrefix
 	cmpNoPrefix
 	cmpSuffix
@@ -175,10 +169,12 @@
 )
 
 var negateMap = map[compareOp]compareOp{
 	cmpUnknown:  cmpUnknown,
 	cmpExist:    cmpNotExist,
+	cmpEqual:    cmpNotEqual,
+	cmpNotEqual: cmpEqual,
 	cmpHas:      cmpHasNot,
 	cmpHasNot:   cmpHas,
 	cmpPrefix:   cmpNoPrefix,
 	cmpNoPrefix: cmpPrefix,
 	cmpSuffix:   cmpNoSuffix,
@@ -189,10 +185,11 @@
 
 func (op compareOp) negate() compareOp { return negateMap[op] }
 
 var negativeMap = map[compareOp]bool{
 	cmpNotExist: true,
+	cmpNotEqual: true,
 	cmpHasNot:   true,
 	cmpNoPrefix: true,
 	cmpNoSuffix: true,
 	cmpNoMatch:  true,
 }
@@ -234,10 +231,19 @@
 	if q == nil {
 		return 0, false
 	}
 	return q.seed, q.seed > 0
 }
+
+// SetDeterministic signals that the result should be the same if the seed is the same.
+func (q *Query) SetDeterministic() *Query {
+	q = createIfNeeded(q)
+	if q.seed <= 0 {
+		q.seed = int(rand.Intn(10000) + 1)
+	}
+	return q
+}
 
 // SetLimit sets the given limit of the query object.
 func (q *Query) SetLimit(limit int) *Query {
 	q = createIfNeeded(q)
 	if limit < 0 {
@@ -273,10 +279,13 @@
 // EnrichNeeded returns true, if the query references a metadata key that
 // is calculated via metadata enrichments.
 func (q *Query) EnrichNeeded() bool {
 	if q == nil {
 		return false
+	}
+	if q.zid.IsValid() {
+		return true
 	}
 	if len(q.actions) > 0 {
 		// Unknown, what an action will use. Example: RSS needs api.KeyPublished.
 		return true
 	}
@@ -298,56 +307,107 @@
 		}
 	}
 	return false
 }
 
+// GetMetaFunc is a function that allows to retieve the metadata for a specific zid.
+type GetMetaFunc func(context.Context, id.Zid) (*meta.Meta, error)
+
+// SelectMetaFunc is a function the returns a list of metadata based on a query.
+type SelectMetaFunc func(context.Context, *Query) ([]*meta.Meta, error)
+
 // RetrieveAndCompile queries the search index and returns a predicate
 // for its results and returns a matching predicate.
-func (q *Query) RetrieveAndCompile(searcher Searcher) Compiled {
+func (q *Query) RetrieveAndCompile(ctx context.Context, searcher Searcher, getMeta GetMetaFunc, selectMeta SelectMetaFunc) (Compiled, error) {
 	if q == nil {
 		return Compiled{
 			PreMatch: matchAlways,
 			Terms: []CompiledTerm{{
 				Match:    matchAlways,
 				Retrieve: alwaysIncluded,
-			}}}
+			}}}, nil
 	}
 	q = q.Clone()
 
 	preMatch := q.preMatch
 	if preMatch == nil {
 		preMatch = matchAlways
 	}
-	result := Compiled{PreMatch: preMatch}
+	contextMeta, err := q.getContext(
+		ctx, preMatch,
+		func(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
+			m, err := getMeta(ctx, zid)
+			return m, err
+		},
+		selectMeta,
+	)
+	if err != nil {
+		return Compiled{}, err
+	}
+	contextSet := metaList2idSet(contextMeta)
+	result := Compiled{
+		hasQuery:    true,
+		seed:        q.seed,
+		pick:        q.pick,
+		order:       q.order,
+		offset:      q.offset,
+		limit:       q.limit,
+		contextMeta: contextMeta,
+		PreMatch:    preMatch,
+		Terms:       []CompiledTerm{},
+	}
 
 	for _, term := range q.terms {
-		cTerm := term.retrievAndCompileTerm(searcher)
+		cTerm := term.retrieveAndCompileTerm(searcher, contextSet)
 		if cTerm.Retrieve == nil {
 			if cTerm.Match == nil {
 				// no restriction on match/retrieve -> all will match
-				return Compiled{
-					PreMatch: preMatch,
-					Terms: []CompiledTerm{{
-						Match:    matchAlways,
-						Retrieve: alwaysIncluded,
-					}}}
+				result.Terms = []CompiledTerm{{
+					Match:    matchAlways,
+					Retrieve: alwaysIncluded,
+				}}
+				break
 			}
 			cTerm.Retrieve = alwaysIncluded
 		}
 		if cTerm.Match == nil {
 			cTerm.Match = matchAlways
 		}
 		result.Terms = append(result.Terms, cTerm)
 	}
+	return result, nil
+}
+
+func metaList2idSet(ml []*meta.Meta) id.Set {
+	if ml == nil {
+		return nil
+	}
+	result := id.NewSetCap(len(ml))
+	for _, m := range ml {
+		result = result.Zid(m.Zid)
+	}
 	return result
 }
 
-func (ct *conjTerms) retrievAndCompileTerm(searcher Searcher) CompiledTerm {
+func (ct *conjTerms) retrieveAndCompileTerm(searcher Searcher, contextSet id.Set) CompiledTerm {
 	match := ct.compileMeta() // Match might add some searches
 	var pred RetrievePredicate
 	if searcher != nil {
 		pred = ct.retrieveIndex(searcher)
+		if contextSet != nil {
+			if pred == nil {
+				pred = contextSet.Contains
+			} else {
+				predSet := id.NewSetCap(len(contextSet))
+				for zid := range contextSet {
+					if pred(zid) {
+						predSet = predSet.Zid(zid)
+					}
+				}
+				pred = predSet.Contains
+			}
+		}
 	}
 	return CompiledTerm{Match: match, Retrieve: pred}
 }
 
 // retrieveIndex and return a predicate to ask for results.
@@ -374,102 +434,20 @@
 	if len(negCalls) == 0 {
 		// Positive search found something, but there is no negative search.
 		return positives.Contains
 	}
 	negatives := retrieveNegatives(negCalls)
+	if negatives == nil {
+		return positives.Contains
+	}
 	return func(zid id.Zid) bool {
 		return positives.Contains(zid) && !negatives.Contains(zid)
 	}
 }
 
-// AfterSearch applies all terms to the metadata list that was searched.
-//
-// This includes sorting, offset, limit, and picking.
-func (q *Query) AfterSearch(metaList []*meta.Meta) []*meta.Meta {
-	if len(metaList) == 0 {
-		return metaList
-	}
-
-	if q == nil {
-		sort.Slice(metaList, func(i, j int) bool { return metaList[i].Zid > metaList[j].Zid })
-		return metaList
-	}
-
-	metaList = q.doPick(metaList)
-
-	if len(q.order) == 0 {
-		if q.pick <= 0 {
-			sort.Slice(metaList, func(i, j int) bool { return metaList[i].Zid > metaList[j].Zid })
-		}
-	} else if q.order[0].isRandom() {
-		metaList = q.sortRandomly(metaList)
-	} else {
-		sort.Slice(metaList, createSortFunc(q.order, metaList))
-	}
-
-	if q.offset > 0 {
-		if q.offset > len(metaList) {
-			return nil
-		}
-		metaList = metaList[q.offset:]
-	}
-	return q.Limit(metaList)
-}
-
-func (q *Query) setSeed() {
-	if q != nil && q.seed <= 0 {
-		q.seed = int(rand.Intn(10000) + 1)
-	}
-}
-
-func (q *Query) doPick(metaList []*meta.Meta) []*meta.Meta {
-	pick := q.pick
-	if pick <= 0 {
-		return metaList
-	}
-	if limit := q.limit; limit > 0 && limit < pick {
-		pick = limit
-	}
-	if pick >= len(metaList) && len(q.order) == 0 {
-		return q.sortRandomly(metaList)
-	}
-	return q.doPickN(metaList, pick)
-}
-func (q *Query) doPickN(metaList []*meta.Meta, pick int) []*meta.Meta {
-	q.setSeed()
-	rnd := rand.New(rand.NewSource(int64(q.seed)))
-	result := make([]*meta.Meta, pick)
-	for i := 0; i < pick; i++ {
-		n := rnd.Intn(pick - i)
-		result[i] = metaList[n]
-		metaList[n] = metaList[len(metaList)-i-1]
-		metaList[len(metaList)-i-1] = nil
-	}
-	return result
-}
-
-func (q *Query) sortRandomly(metaList []*meta.Meta) []*meta.Meta {
-	// Optimization: RANDOM LIMIT n, where n < len(metaList) is essentially a PICK n.
-	if limit := q.limit; limit > 0 && limit < len(metaList) {
-		return q.doPickN(metaList, limit)
-	}
-
-	sort.Slice(metaList, func(i, j int) bool { return metaList[i].Zid > metaList[j].Zid })
-	q.setSeed()
-	rnd := rand.New(rand.NewSource(int64(q.seed)))
-	rnd.Shuffle(
-		len(metaList),
-		func(i, j int) { metaList[i], metaList[j] = metaList[j], metaList[i] },
-	)
-	return metaList
-}
-
 // Limit returns only s.GetLimit() elements of the given list.
 func (q *Query) Limit(metaList []*meta.Meta) []*meta.Meta {
 	if q == nil {
 		return metaList
 	}
-	if limit := q.limit; limit > 0 && limit < len(metaList) {
-		return metaList[:limit]
-	}
-	return metaList
+	return limitElements(metaList, q.limit)
 }

Index: query/retrieve.go
==================================================================
--- query/retrieve.go
+++ query/retrieve.go
@@ -14,12 +14,12 @@
 
 import (
 	"fmt"
 	"strings"
 
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/id"
 )
 
 type searchOp struct {
 	s  string
 	op compareOp
@@ -26,14 +26,15 @@
 }
 type searchFunc func(string) id.Set
 type searchCallMap map[searchOp]searchFunc
 
 var cmpPred = map[compareOp]func(string, string) bool{
-	cmpHas:    func(s, t string) bool { return s == t },
+	cmpEqual:  stringEqual,
 	cmpPrefix: strings.HasPrefix,
 	cmpSuffix: strings.HasSuffix,
 	cmpMatch:  strings.Contains,
+	cmpHas:    strings.Contains, // the "has" operator have string semantics here in a index search
 }
 
 func (scm searchCallMap) addSearch(s string, op compareOp, sf searchFunc) {
 	pred := cmpPred[op]
 	for k := range scm {
@@ -153,17 +154,17 @@
 	return negatives
 }
 
 func getSearchFunc(searcher Searcher, op compareOp) searchFunc {
 	switch op {
-	case cmpHas:
+	case cmpEqual:
 		return searcher.SearchEqual
 	case cmpPrefix:
 		return searcher.SearchPrefix
 	case cmpSuffix:
 		return searcher.SearchSuffix
-	case cmpMatch:
+	case cmpMatch, cmpHas: // for index search we assume string semantics
 		return searcher.SearchContains
 	default:
 		panic(fmt.Sprintf("Unexpected value of comparison operation: %v", op))
 	}
 }

Index: query/select.go
==================================================================
--- query/select.go
+++ query/select.go
@@ -13,14 +13,14 @@
 import (
 	"fmt"
 	"strings"
 	"unicode/utf8"
 
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder/textenc"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type matchValueFunc func(value string) bool
 
 func matchValueNever(string) bool { return false }
@@ -99,21 +99,21 @@
 	case meta.TypeIDSet:
 		return createMatchIDSetFunc(values, addSearch)
 	case meta.TypeTagSet:
 		return createMatchTagSetFunc(values, addSearch)
 	case meta.TypeWord:
-		return createMatchWordOrStringFunc(values, addSearch)
+		return createMatchWordFunc(values, addSearch)
 	case meta.TypeWordSet:
 		return createMatchWordSetFunc(values, addSearch)
 	case meta.TypeZettelmarkup:
 		return createMatchZmkFunc(values, addSearch)
 	}
-	return createMatchWordOrStringFunc(values, addSearch)
+	return createMatchStringFunc(values, addSearch)
 }
 
 func createMatchIDFunc(values []expValue, addSearch addSearchFunc) matchValueFunc {
-	preds := valuesToStringPredicates(values, addSearch)
+	preds := valuesToWordPredicates(values, addSearch)
 	return func(value string) bool {
 		for _, pred := range preds {
 			if !pred(value) {
 				return false
 			}
@@ -121,11 +121,11 @@
 		return true
 	}
 }
 
 func createMatchIDSetFunc(values []expValue, addSearch addSearchFunc) matchValueFunc {
-	predList := valuesToStringSetPredicates(preprocessSet(values), addSearch)
+	predList := valuesToWordSetPredicates(preprocessSet(values), addSearch)
 	return func(value string) bool {
 		ids := meta.ListFromValue(value)
 		for _, preds := range predList {
 			for _, pred := range preds {
 				if !pred(ids) {
@@ -136,11 +136,11 @@
 		return true
 	}
 }
 
 func createMatchTagSetFunc(values []expValue, addSearch addSearchFunc) matchValueFunc {
-	predList := valuesToStringSetPredicates(processTagSet(preprocessSet(sliceToLower(values))), addSearch)
+	predList := valuesToWordSetPredicates(processTagSet(preprocessSet(sliceToLower(values))), addSearch)
 	return func(value string) bool {
 		tags := meta.ListFromValue(value)
 		// Remove leading '#' from each tag
 		for i, tag := range tags {
 			tags[i] = meta.CleanTag(tag)
@@ -171,11 +171,24 @@
 		result[i] = tags
 	}
 	return result
 }
 
-func createMatchWordOrStringFunc(values []expValue, addSearch addSearchFunc) matchValueFunc {
+func createMatchWordFunc(values []expValue, addSearch addSearchFunc) matchValueFunc {
+	preds := valuesToWordPredicates(sliceToLower(values), addSearch)
+	return func(value string) bool {
+		value = strings.ToLower(value)
+		for _, pred := range preds {
+			if !pred(value) {
+				return false
+			}
+		}
+		return true
+	}
+}
+
+func createMatchStringFunc(values []expValue, addSearch addSearchFunc) matchValueFunc {
 	preds := valuesToStringPredicates(sliceToLower(values), addSearch)
 	return func(value string) bool {
 		value = strings.ToLower(value)
 		for _, pred := range preds {
 			if !pred(value) {
@@ -185,11 +198,11 @@
 		return true
 	}
 }
 
 func createMatchWordSetFunc(values []expValue, addSearch addSearchFunc) matchValueFunc {
-	predsList := valuesToStringSetPredicates(preprocessSet(sliceToLower(values)), addSearch)
+	predsList := valuesToWordSetPredicates(preprocessSet(sliceToLower(values)), addSearch)
 	return func(value string) bool {
 		words := meta.ListFromValue(value)
 		for _, preds := range predsList {
 			for _, pred := range preds {
 				if !pred(words) {
@@ -217,13 +230,13 @@
 	negPreds := make([]stringPredicate, 0, len(values))
 	for _, v := range values {
 		for _, word := range strfun.NormalizeWords(v.value) {
 			if cmpOp := v.op; cmpOp.isNegated() {
 				cmpOp = cmpOp.negate()
-				negPreds = append(negPreds, createStringCompareFunc(word, cmpOp))
+				negPreds = append(negPreds, createWordCompareFunc(word, cmpOp))
 			} else {
-				normPreds = append(normPreds, createStringCompareFunc(word, cmpOp))
+				normPreds = append(normPreds, createWordCompareFunc(word, cmpOp))
 				addSearch(expValue{word, cmpOp}) // addSearch only for positive selections
 			}
 		}
 	}
 	return func(metaValue string) bool {
@@ -305,23 +318,62 @@
 type stringPredicate func(string) bool
 
 func valuesToStringPredicates(values []expValue, addSearch addSearchFunc) []stringPredicate {
 	result := make([]stringPredicate, len(values))
 	for i, v := range values {
-		if !v.op.isNegated() {
+		op := disambiguatedStringOp(v.op)
+		if !op.isNegated() {
+			addSearch(v) // addSearch only for positive selections
+		}
+		result[i] = createStringCompareFunc(v.value, op)
+	}
+	return result
+}
+
+func disambiguatedStringOp(cmpOp compareOp) compareOp {
+	switch cmpOp {
+	case cmpHas:
+		return cmpMatch
+	case cmpHasNot:
+		return cmpNoMatch
+	default:
+		return cmpOp
+	}
+}
+
+func createStringCompareFunc(cmpVal string, cmpOp compareOp) stringPredicate {
+	return createWordCompareFunc(cmpVal, cmpOp)
+}
+
+func valuesToWordPredicates(values []expValue, addSearch addSearchFunc) []stringPredicate {
+	result := make([]stringPredicate, len(values))
+	for i, v := range values {
+		op := disambiguateWordOp(v.op)
+		if !op.isNegated() {
 			addSearch(v) // addSearch only for positive selections
 		}
-		result[i] = createStringCompareFunc(v.value, v.op)
+		result[i] = createWordCompareFunc(v.value, op)
 	}
 	return result
 }
 
-func createStringCompareFunc(cmpVal string, cmpOp compareOp) stringPredicate {
+func disambiguateWordOp(cmpOp compareOp) compareOp {
 	switch cmpOp {
 	case cmpHas:
-		return func(metaVal string) bool { return metaVal == cmpVal }
+		return cmpEqual
 	case cmpHasNot:
+		return cmpNotEqual
+	default:
+		return cmpOp
+	}
+}
+
+func createWordCompareFunc(cmpVal string, cmpOp compareOp) stringPredicate {
+	switch cmpOp {
+	case cmpEqual:
+		return func(metaVal string) bool { return metaVal == cmpVal }
+	case cmpNotEqual:
 		return func(metaVal string) bool { return metaVal != cmpVal }
 	case cmpPrefix:
 		return func(metaVal string) bool { return strings.HasPrefix(metaVal, cmpVal) }
 	case cmpNoPrefix:
 		return func(metaVal string) bool { return !strings.HasPrefix(metaVal, cmpVal) }
@@ -331,28 +383,30 @@
 		return func(metaVal string) bool { return !strings.HasSuffix(metaVal, cmpVal) }
 	case cmpMatch:
 		return func(metaVal string) bool { return strings.Contains(metaVal, cmpVal) }
 	case cmpNoMatch:
 		return func(metaVal string) bool { return !strings.Contains(metaVal, cmpVal) }
+	case cmpHas, cmpHasNot:
+		panic(fmt.Sprintf("operator %d not disambiguated with value %q", cmpOp, cmpVal))
 	default:
 		panic(fmt.Sprintf("Unknown compare operation %d with value %q", cmpOp, cmpVal))
 	}
 }
 
 type stringSetPredicate func(value []string) bool
 
-func valuesToStringSetPredicates(values [][]expValue, addSearch addSearchFunc) [][]stringSetPredicate {
+func valuesToWordSetPredicates(values [][]expValue, addSearch addSearchFunc) [][]stringSetPredicate {
 	result := make([][]stringSetPredicate, len(values))
 	for i, val := range values {
 		elemPreds := make([]stringSetPredicate, len(val))
 		for j, v := range val {
 			opVal := v.value // loop variable is used in closure --> save needed value
-			switch v.op {
-			case cmpHas:
+			switch op := disambiguateWordOp(v.op); op {
+			case cmpEqual:
 				addSearch(v) // addSearch only for positive selections
 				elemPreds[j] = makeStringSetPredicate(opVal, stringEqual, true)
-			case cmpHasNot:
+			case cmpNotEqual:
 				elemPreds[j] = makeStringSetPredicate(opVal, stringEqual, false)
 			case cmpPrefix:
 				addSearch(v)
 				elemPreds[j] = makeStringSetPredicate(opVal, strings.HasPrefix, true)
 			case cmpNoPrefix:
@@ -365,12 +419,14 @@
 			case cmpMatch:
 				addSearch(v)
 				elemPreds[j] = makeStringSetPredicate(opVal, strings.Contains, true)
 			case cmpNoMatch:
 				elemPreds[j] = makeStringSetPredicate(opVal, strings.Contains, false)
+			case cmpHas, cmpHasNot:
+				panic(fmt.Sprintf("operator %d not disambiguated with value %q", op, opVal))
 			default:
-				panic(fmt.Sprintf("Unknown compare operation %d with value %q", v.op, opVal))
+				panic(fmt.Sprintf("Unknown compare operation %d with value %q", op, opVal))
 			}
 		}
 		result[i] = elemPreds
 	}
 	return result

Index: query/select_test.go
==================================================================
--- query/select_test.go
+++ query/select_test.go
@@ -9,21 +9,22 @@
 //-----------------------------------------------------------------------------
 
 package query_test
 
 import (
+	"context"
 	"testing"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func TestMatchZidNegate(t *testing.T) {
 	q := query.Parse(api.KeyID + api.SearchOperatorHasNot + string(api.ZidVersion) + " " + api.KeyID + api.SearchOperatorHasNot + string(api.ZidLicense))
-	compiled := q.RetrieveAndCompile(nil)
+	compiled, _ := q.RetrieveAndCompile(context.Background(), nil, nil, nil)
 
 	testCases := []struct {
 		zid api.ZettelID
 		exp bool
 	}{

Index: query/sorter.go
==================================================================
--- query/sorter.go
+++ query/sorter.go
@@ -12,11 +12,11 @@
 
 import (
 	"strconv"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type sortFunc func(i, j int) bool
 
 func createSortFunc(order []sortOrder, ml []*meta.Meta) sortFunc {

Index: tests/client/client_test.go
==================================================================
--- tests/client/client_test.go
+++ tests/client/client_test.go
@@ -47,14 +47,14 @@
 	}
 }
 
 func TestListZettel(t *testing.T) {
 	const (
-		ownerZettel      = 47
-		configRoleZettel = 29
-		writerZettel     = ownerZettel - 23
-		readerZettel     = ownerZettel - 23
+		ownerZettel      = 46
+		configRoleZettel = 28
+		writerZettel     = ownerZettel - 22
+		readerZettel     = ownerZettel - 22
 		creatorZettel    = 7
 		publicZettel     = 4
 	)
 
 	testdata := []struct {
@@ -88,29 +88,30 @@
 			if got != tc.exp {
 				tt.Errorf("List of length %d expected, but got %d\n%v", tc.exp, got, l)
 			}
 		})
 	}
-	q, h, l, err := c.ListZettelJSON(context.Background(), api.KeyRole+api.SearchOperatorHas+api.ValueRoleConfiguration)
+	search := api.KeyRole + api.SearchOperatorHas + api.ValueRoleConfiguration + " ORDER id"
+	q, h, l, err := c.ListZettelJSON(context.Background(), search)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-	expQ := "role:configuration"
+	expQ := "role:configuration ORDER id"
 	if q != expQ {
 		t.Errorf("Query should be %q, but is %q", expQ, q)
 	}
-	expH := "role HAS configuration"
+	expH := "role HAS configuration ORDER id"
 	if h != expH {
 		t.Errorf("Human should be %q, but is %q", expH, h)
 	}
 	got := len(l)
 	if got != configRoleZettel {
 		t.Errorf("List of length %d expected, but got %d\n%v", configRoleZettel, got, l)
 	}
 
-	pl, err := c.ListZettel(context.Background(), api.KeyRole+api.SearchOperatorHas+api.ValueRoleConfiguration)
+	pl, err := c.ListZettel(context.Background(), search)
 	if err != nil {
 		t.Error(err)
 		return
 	}
 	compareZettelList(t, pl, l)
@@ -170,11 +171,11 @@
 	t.Parallel()
 	c := getClient()
 	c.SetAuth("owner", "owner")
 	encodings := []api.EncodingEnum{
 		api.EncoderHTML,
-		api.EncoderSexpr,
+		api.EncoderSz,
 		api.EncoderText,
 	}
 	for _, enc := range encodings {
 		content, err := c.GetParsedZettel(context.Background(), api.ZidDefaultHome, enc)
 		if err != nil {
@@ -230,56 +231,56 @@
 	}
 	checkListZid(t, l, 0, api.ZidTemplateNewZettel)
 	checkListZid(t, l, 1, api.ZidTemplateNewUser)
 }
 
-func TestGetZettelContext(t *testing.T) {
-	const (
-		allUserZid = api.ZettelID("20211019200500")
-		ownerZid   = api.ZettelID("20210629163300")
-		writerZid  = api.ZettelID("20210629165000")
-		readerZid  = api.ZettelID("20210629165024")
-		creatorZid = api.ZettelID("20210629165050")
-		limitAll   = 3
-	)
-	t.Parallel()
-	c := getClient()
-	c.SetAuth("owner", "owner")
-	rl, err := c.GetZettelContext(context.Background(), ownerZid, client.DirBoth, 0, limitAll)
-	if err != nil {
-		t.Error(err)
-		return
-	}
-	if !checkZid(t, ownerZid, rl.ID) {
-		return
-	}
-	l := rl.List
-	if got := len(l); got != limitAll {
-		t.Errorf("Expected list of length %d, got %d", limitAll, got)
-		t.Error(rl)
-		return
-	}
-	checkListZid(t, l, 0, allUserZid)
-	// checkListZid(t, l, 1, writerZid)
-	// checkListZid(t, l, 2, readerZid)
-	checkListZid(t, l, 1, creatorZid)
-
-	rl, err = c.GetZettelContext(context.Background(), ownerZid, client.DirBackward, 0, 0)
-	if err != nil {
-		t.Error(err)
-		return
-	}
-	if !checkZid(t, ownerZid, rl.ID) {
-		return
-	}
-	l = rl.List
-	if got, exp := len(l), 4; got != exp {
-		t.Errorf("Expected list of length %d, got %d", exp, got)
-		return
-	}
-	checkListZid(t, l, 0, allUserZid)
-}
+// func TestGetZettelContext(t *testing.T) {
+// 	const (
+// 		allUserZid = api.ZettelID("20211019200500")
+// 		ownerZid   = api.ZettelID("20210629163300")
+// 		writerZid  = api.ZettelID("20210629165000")
+// 		readerZid  = api.ZettelID("20210629165024")
+// 		creatorZid = api.ZettelID("20210629165050")
+// 		limitAll   = 3
+// 	)
+// 	t.Parallel()
+// 	c := getClient()
+// 	c.SetAuth("owner", "owner")
+// 	rl, err := c.GetZettelContext(context.Background(), ownerZid, client.DirBoth, 0, limitAll)
+// 	if err != nil {
+// 		t.Error(err)
+// 		return
+// 	}
+// 	if !checkZid(t, ownerZid, rl.ID) {
+// 		return
+// 	}
+// 	l := rl.List
+// 	if got := len(l); got != limitAll {
+// 		t.Errorf("Expected list of length %d, got %d", limitAll, got)
+// 		t.Error(rl)
+// 		return
+// 	}
+// 	checkListZid(t, l, 0, allUserZid)
+// 	// checkListZid(t, l, 1, writerZid)
+// 	// checkListZid(t, l, 2, readerZid)
+// 	checkListZid(t, l, 1, creatorZid)
+
+// 	rl, err = c.GetZettelContext(context.Background(), ownerZid, client.DirBackward, 0, 0)
+// 	if err != nil {
+// 		t.Error(err)
+// 		return
+// 	}
+// 	if !checkZid(t, ownerZid, rl.ID) {
+// 		return
+// 	}
+// 	l = rl.List
+// 	if got, exp := len(l), 4; got != exp {
+// 		t.Errorf("Expected list of length %d, got %d", exp, got)
+// 		return
+// 	}
+// 	checkListZid(t, l, 0, allUserZid)
+// }
 
 func TestGetUnlinkedReferences(t *testing.T) {
 	t.Parallel()
 	c := getClient()
 	c.SetAuth("owner", "owner")

Index: tests/markdown_test.go
==================================================================
--- tests/markdown_test.go
+++ tests/markdown_test.go
@@ -19,22 +19,22 @@
 	"testing"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder"
 	_ "zettelstore.de/z/encoder/htmlenc"
 	_ "zettelstore.de/z/encoder/mdenc"
-	_ "zettelstore.de/z/encoder/sexprenc"
 	_ "zettelstore.de/z/encoder/shtmlenc"
+	_ "zettelstore.de/z/encoder/szenc"
 	_ "zettelstore.de/z/encoder/textenc"
 	_ "zettelstore.de/z/encoder/zmkenc"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
 	_ "zettelstore.de/z/parser/markdown"
 	_ "zettelstore.de/z/parser/zettelmark"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type markdownTestCase struct {
 	Markdown  string `json:"markdown"`
 	HTML      string `json:"html"`

Index: tests/naughtystrings_test.go
==================================================================
--- tests/naughtystrings_test.go
+++ tests/naughtystrings_test.go
@@ -16,14 +16,14 @@
 	"os"
 	"path/filepath"
 	"testing"
 
 	_ "zettelstore.de/z/cmd"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Test all parser / encoder with a list of "naughty strings", i.e. unusual strings
 // that often crash software.
 

Index: tests/regression_test.go
==================================================================
--- tests/regression_test.go
+++ tests/regression_test.go
@@ -24,21 +24,21 @@
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/box/manager"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/meta"
 
 	_ "zettelstore.de/z/box/dirbox"
 )
 
 var encodings = []api.EncodingEnum{
 	api.EncoderHTML,
-	api.EncoderSexpr,
+	api.EncoderSz,
 	api.EncoderText,
 }
 
 func getFileBoxes(wd, kind string) (root string, boxes []box.ManagedBox) {
 	root = filepath.Clean(filepath.Join(wd, "..", "testdata", kind))

Index: tools/build.go
==================================================================
--- tools/build.go
+++ tools/build.go
@@ -484,10 +484,36 @@
 		return err
 	}
 	_, err = io.Copy(w, zsFile)
 	return err
 }
+
+func cmdTools() error {
+	tools := []struct{ name, pack string }{
+		{"shadow", "golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow@latest"},
+		{"unparam", "mvdan.cc/unparam@latest"},
+		{"staticcheck", "honnef.co/go/tools/cmd/staticcheck@latest"},
+		{"govulncheck", "golang.org/x/vuln/cmd/govulncheck@latest"},
+	}
+	for _, tool := range tools {
+		err := doGoInstall(tool.pack)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+func doGoInstall(pack string) error {
+	out, err := executeCommand(nil, "go", "install", pack)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "Unable to install package", pack)
+		if len(out) > 0 {
+			fmt.Fprintln(os.Stderr, out)
+		}
+	}
+	return err
+}
 
 func cmdClean() error {
 	for _, dir := range []string{"bin", "releases"} {
 		err := os.RemoveAll(dir)
 		if err != nil {
@@ -527,18 +553,17 @@
   manual    Create a ZIP file with all manual zettel
   relcheck  Check current working state for release.
   release   Create the software for various platforms and put them in
             appropriate named ZIP files.
   testapi   Start a Zettelstore and execute API tests.
+  tools     Install/update tools needed for building Zettelstore.
   version   Print the current version of the software.
 
 All commands can be abbreviated as long as they remain unique.`)
 }
 
-var (
-	verbose bool
-)
+var verbose bool
 
 func main() {
 	flag.BoolVar(&verbose, "v", false, "Verbose output")
 	flag.Parse()
 	var err error
@@ -559,12 +584,14 @@
 			fmt.Print(getVersion())
 		case "ch", "che", "chec", "check":
 			err = cmdCheck(false)
 		case "relc", "relch", "relche", "relchec", "relcheck":
 			err = cmdCheck(true)
-		case "t", "te", "tes", "test", "testa", "testap", "testapi":
+		case "te", "tes", "test", "testa", "testap", "testapi":
 			cmdTestAPI()
+		case "to", "too", "tool", "tools":
+			err = cmdTools()
 		case "h", "he", "hel", "help":
 			cmdHelp()
 		default:
 			fmt.Fprintf(os.Stderr, "Unknown command %q\n", args[0])
 			cmdHelp()

Index: usecase/authenticate.go
==================================================================
--- usecase/authenticate.go
+++ usecase/authenticate.go
@@ -17,14 +17,14 @@
 	"time"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/auth/cred"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // AuthenticatePort is the interface used by this use case.
 type AuthenticatePort interface {
 	GetMeta(context.Context, id.Zid) (*meta.Meta, error)

DELETED usecase/context.go
Index: usecase/context.go
==================================================================
--- usecase/context.go
+++ usecase/context.go
@@ -1,295 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2021-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package usecase
-
-import (
-	"context"
-
-	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
-	"zettelstore.de/z/query"
-)
-
-// ZettelContextPort is the interface used by this use case.
-type ZettelContextPort interface {
-	// GetMeta retrieves just the meta data of a specific zettel.
-	GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error)
-
-	// SelectMeta returns all zettel metadata that match the selection criteria.
-	SelectMeta(ctx context.Context, q *query.Query) ([]*meta.Meta, error)
-}
-
-// ZettelContextConfig is the interface to allow the usecase to read some config data.
-type ZettelContextConfig interface {
-	// Get returns a config value that might be user-specific.
-	Get(ctx context.Context, m *meta.Meta, key string) string
-}
-
-// ZettelContext is the data for this use case.
-type ZettelContext struct {
-	port   ZettelContextPort
-	config ZettelContextConfig
-}
-
-// NewZettelContext creates a new use case.
-func NewZettelContext(port ZettelContextPort, config ZettelContextConfig) ZettelContext {
-	return ZettelContext{port: port, config: config}
-}
-
-// ZettelContextDirection determines the way, the context is calculated.
-type ZettelContextDirection int
-
-// Constant values for ZettelContextDirection
-const (
-	_                     ZettelContextDirection = iota
-	ZettelContextForward                         // Traverse all forwarding links
-	ZettelContextBackward                        // Traverse all backwaring links
-	ZettelContextBoth                            // Traverse both directions
-)
-
-// Run executes the use case.
-func (uc ZettelContext) Run(ctx context.Context, zid id.Zid, dir ZettelContextDirection, maxCost, limit int) (result []*meta.Meta, err error) {
-	start, err := uc.port.GetMeta(ctx, zid)
-	if err != nil {
-		return nil, err
-	}
-	tasks := newQueue(start, maxCost, limit)
-	isBackward := dir == ZettelContextBoth || dir == ZettelContextBackward
-	isForward := dir == ZettelContextBoth || dir == ZettelContextForward
-	for {
-		m, cost := tasks.next()
-		if m == nil {
-			break
-		}
-		result = append(result, m)
-
-		for _, p := range m.ComputedPairsRest() {
-			tasks.addPair(ctx, uc.port, p.Key, p.Value, cost, isBackward, isForward)
-		}
-		if tags, found := m.GetList(api.KeyTags); found {
-			for _, tag := range tags {
-				tasks.addSameTag(ctx, uc.port, tag, cost)
-			}
-		}
-	}
-	return result, nil
-}
-
-type ztlCtxTask struct {
-	next *ztlCtxTask
-	prev *ztlCtxTask
-	meta *meta.Meta
-	cost int
-}
-
-type contextQueue struct {
-	seen    id.Set
-	first   *ztlCtxTask
-	last    *ztlCtxTask
-	maxCost int
-	limit   int
-	tagCost map[string][]*meta.Meta
-}
-
-func newQueue(m *meta.Meta, maxCost, limit int) *contextQueue {
-	task := &ztlCtxTask{
-		next: nil,
-		prev: nil,
-		meta: m,
-		cost: 0,
-	}
-	result := &contextQueue{
-		seen:    id.NewSet(),
-		first:   task,
-		last:    task,
-		maxCost: maxCost,
-		limit:   limit,
-		tagCost: make(map[string][]*meta.Meta, 1024),
-	}
-	return result
-}
-
-func (zc *contextQueue) addPair(
-	ctx context.Context, port ZettelContextPort,
-	key, value string,
-	curCost int, isBackward, isForward bool,
-) {
-	if key == api.KeyBack {
-		return
-	}
-	newCost := curCost + contextCost(key)
-	if key == api.KeyBackward {
-		if isBackward {
-			zc.addIDSet(ctx, port, newCost, value)
-		}
-		return
-	}
-	if key == api.KeyForward {
-		if isForward {
-			zc.addIDSet(ctx, port, newCost, value)
-		}
-		return
-	}
-	hasInverse := meta.Inverse(key) != ""
-	if (!hasInverse || !isBackward) && (hasInverse || !isForward) {
-		return
-	}
-	if t := meta.Type(key); t == meta.TypeID {
-		zc.addID(ctx, port, newCost, value)
-	} else if t == meta.TypeIDSet {
-		zc.addIDSet(ctx, port, newCost, value)
-	}
-}
-
-func contextCost(key string) int {
-	switch key {
-	case api.KeyFolge, api.KeyPrecursor:
-		return 1
-	case api.KeySuccessors, api.KeyPredecessor:
-		return 2
-	}
-	return 3
-}
-
-func (zc *contextQueue) addID(ctx context.Context, port ZettelContextPort, newCost int, value string) {
-	if zc.costMaxed(newCost) {
-		return
-	}
-
-	zid, err := id.Parse(value)
-	if err != nil {
-		return
-	}
-	m, err := port.GetMeta(ctx, zid)
-	if err != nil {
-		return
-	}
-	zc.addMeta(m, newCost)
-}
-func (zc *contextQueue) addMeta(m *meta.Meta, newCost int) {
-	task := &ztlCtxTask{next: nil, prev: nil, meta: m, cost: newCost}
-	if zc.first == nil {
-		zc.first = task
-		zc.last = task
-		return
-	}
-
-	// Search backward for a task t with at most the same cost
-	for t := zc.last; t != nil; t = t.prev {
-		if t.cost <= task.cost {
-			// Found!
-			if t.next != nil {
-				t.next.prev = task
-			}
-			task.next = t.next
-			t.next = task
-			task.prev = t
-			if task.next == nil {
-				zc.last = task
-			}
-			return
-		}
-	}
-
-	// We have not found a task, therefore the new task is the first one
-	task.next = zc.first
-	zc.first.prev = task
-	zc.first = task
-}
-
-func (zc *contextQueue) costMaxed(newCost int) bool {
-	return (zc.maxCost > 0 && newCost > zc.maxCost) || zc.hasLimit()
-}
-
-func (zc *contextQueue) addIDSet(ctx context.Context, port ZettelContextPort, newCost int, value string) {
-	elems := meta.ListFromValue(value)
-	refCost := referenceCost(newCost, len(elems))
-	for _, val := range elems {
-		zc.addID(ctx, port, refCost, val)
-	}
-}
-
-func referenceCost(baseCost int, numReferences int) int {
-	baseCost++
-	if numReferences < 5 {
-		return baseCost
-	}
-	if numReferences < 9 {
-		return baseCost * 2
-	}
-	if numReferences < 17 {
-		return baseCost * 3
-	}
-	if numReferences < 33 {
-		return baseCost * 4
-	}
-	if numReferences < 65 {
-		return baseCost * 5
-	}
-	return baseCost * numReferences / 8
-}
-
-func (zc *contextQueue) addSameTag(ctx context.Context, port ZettelContextPort, tag string, baseCost int) {
-	tagMetas, found := zc.tagCost[tag]
-	if !found {
-		q := query.Parse(api.KeyTags + api.SearchOperatorHas + tag)
-		ml, err := port.SelectMeta(ctx, q)
-		if err != nil {
-			return
-		}
-		tagMetas = ml
-		zc.tagCost[tag] = ml
-	}
-	cost := tagCost(baseCost, len(tagMetas))
-	if zc.costMaxed(cost) {
-		return
-	}
-	for _, m := range tagMetas {
-		zc.addMeta(m, cost)
-	}
-}
-
-func tagCost(baseCost, numTags int) int {
-	if numTags < 5 {
-		return baseCost + numTags
-	}
-	return (baseCost + 2) * (numTags + 1) / 4
-}
-
-func (zc *contextQueue) next() (*meta.Meta, int) {
-	if zc.hasLimit() {
-		return nil, -1
-	}
-	for zc.first != nil {
-		task := zc.first
-		zc.first = task.next
-		if zc.first == nil {
-			zc.last = nil
-		} else {
-			zc.first.prev = nil
-		}
-		m := task.meta
-		zid := m.Zid
-		_, found := zc.seen[zid]
-		if found {
-			continue
-		}
-		zc.seen.Zid(zid)
-		return m, task.cost
-	}
-	return nil, -1
-}
-
-func (zc *contextQueue) hasLimit() bool {
-	limit := zc.limit
-	return limit > 0 && len(zc.seen) > limit
-}

Index: usecase/create_zettel.go
==================================================================
--- usecase/create_zettel.go
+++ usecase/create_zettel.go
@@ -14,20 +14,20 @@
 	"context"
 	"time"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/logger"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // CreateZettelPort is the interface used by this use case.
 type CreateZettelPort interface {
 	// CreateZettel creates a new zettel.
-	CreateZettel(ctx context.Context, zettel domain.Zettel) (id.Zid, error)
+	CreateZettel(ctx context.Context, zettel zettel.Zettel) (id.Zid, error)
 }
 
 // CreateZettel is the data for this use case.
 type CreateZettel struct {
 	log      *logger.Logger
@@ -43,48 +43,48 @@
 		port:     port,
 	}
 }
 
 // PrepareCopy the zettel for further modification.
-func (*CreateZettel) PrepareCopy(origZettel domain.Zettel) domain.Zettel {
+func (*CreateZettel) PrepareCopy(origZettel zettel.Zettel) zettel.Zettel {
 	m := origZettel.Meta.Clone()
 	if title, found := m.Get(api.KeyTitle); found {
 		m.Set(api.KeyTitle, prependTitle(title, "Copy", "Copy of "))
 	}
 	setReadonly(m)
 	content := origZettel.Content
 	content.TrimSpace()
-	return domain.Zettel{Meta: m, Content: content}
+	return zettel.Zettel{Meta: m, Content: content}
 }
 
 // PrepareVersion the zettel for further modification.
-func (*CreateZettel) PrepareVersion(origZettel domain.Zettel) domain.Zettel {
+func (*CreateZettel) PrepareVersion(origZettel zettel.Zettel) zettel.Zettel {
 	origMeta := origZettel.Meta
 	m := origMeta.Clone()
 	m.Set(api.KeyPredecessor, origMeta.Zid.String())
 	setReadonly(m)
 	content := origZettel.Content
 	content.TrimSpace()
-	return domain.Zettel{Meta: m, Content: content}
+	return zettel.Zettel{Meta: m, Content: content}
 }
 
 // PrepareFolge the zettel for further modification.
-func (*CreateZettel) PrepareFolge(origZettel domain.Zettel) domain.Zettel {
+func (*CreateZettel) PrepareFolge(origZettel zettel.Zettel) zettel.Zettel {
 	origMeta := origZettel.Meta
 	m := meta.New(id.Invalid)
 	if title, found := origMeta.Get(api.KeyTitle); found {
 		m.Set(api.KeyTitle, prependTitle(title, "Folge", "Folge of "))
 	}
 	m.SetNonEmpty(api.KeyRole, origMeta.GetDefault(api.KeyRole, ""))
 	m.SetNonEmpty(api.KeyTags, origMeta.GetDefault(api.KeyTags, ""))
 	m.SetNonEmpty(api.KeySyntax, origMeta.GetDefault(api.KeySyntax, ""))
 	m.Set(api.KeyPrecursor, origMeta.Zid.String())
-	return domain.Zettel{Meta: m, Content: domain.NewContent(nil)}
+	return zettel.Zettel{Meta: m, Content: zettel.NewContent(nil)}
 }
 
 // PrepareNew the zettel for further modification.
-func (*CreateZettel) PrepareNew(origZettel domain.Zettel) domain.Zettel {
+func (*CreateZettel) PrepareNew(origZettel zettel.Zettel) zettel.Zettel {
 	m := meta.New(id.Invalid)
 	om := origZettel.Meta
 	m.SetNonEmpty(api.KeyTitle, om.GetDefault(api.KeyTitle, ""))
 	m.SetNonEmpty(api.KeyRole, om.GetDefault(api.KeyRole, ""))
 	m.SetNonEmpty(api.KeyTags, om.GetDefault(api.KeyTags, ""))
@@ -96,11 +96,11 @@
 			m.Set(key[prefixLen:], pair.Value)
 		}
 	}
 	content := origZettel.Content
 	content.TrimSpace()
-	return domain.Zettel{Meta: m, Content: content}
+	return zettel.Zettel{Meta: m, Content: content}
 }
 
 func prependTitle(title, s0, s1 string) string {
 	if len(title) > 0 {
 		return s1 + title
@@ -118,11 +118,11 @@
 		m.Set(api.KeyReadOnly, api.ValueFalse)
 	}
 }
 
 // Run executes the use case.
-func (uc *CreateZettel) Run(ctx context.Context, zettel domain.Zettel) (id.Zid, error) {
+func (uc *CreateZettel) Run(ctx context.Context, zettel zettel.Zettel) (id.Zid, error) {
 	m := zettel.Meta
 	if m.Zid.IsValid() {
 		return m.Zid, nil // TODO: new error: already exists
 	}
 

Index: usecase/delete_zettel.go
==================================================================
--- usecase/delete_zettel.go
+++ usecase/delete_zettel.go
@@ -11,12 +11,12 @@
 package usecase
 
 import (
 	"context"
 
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/logger"
+	"zettelstore.de/z/zettel/id"
 )
 
 // DeleteZettelPort is the interface used by this use case.
 type DeleteZettelPort interface {
 	// DeleteZettel removes the zettel from the box.

Index: usecase/evaluate.go
==================================================================
--- usecase/evaluate.go
+++ usecase/evaluate.go
@@ -13,16 +13,16 @@
 import (
 	"context"
 
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/evaluator"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Evaluate is the data for this use case.
 type Evaluate struct {
 	rtConfig  config.Config
@@ -77,13 +77,13 @@
 func (uc *Evaluate) GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error) {
 	return uc.getMeta.Run(ctx, zid)
 }
 
 // GetZettel retrieves the full zettel of a given zettel identifier.
-func (uc *Evaluate) GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
+func (uc *Evaluate) GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error) {
 	return uc.getZettel.Run(ctx, zid)
 }
 
 // SelectMeta returns a list of metadata that comply to the given selection criteria.
 func (uc *Evaluate) SelectMeta(ctx context.Context, q *query.Query) ([]*meta.Meta, error) {
 	return uc.listMeta.Run(ctx, q)
 }

Index: usecase/get_all_meta.go
==================================================================
--- usecase/get_all_meta.go
+++ usecase/get_all_meta.go
@@ -11,12 +11,12 @@
 package usecase
 
 import (
 	"context"
 
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // GetAllMetaPort is the interface used by this use case.
 type GetAllMetaPort interface {
 	// GetAllMeta retrieves just the meta data of a specific zettel.

Index: usecase/get_meta.go
==================================================================
--- usecase/get_meta.go
+++ usecase/get_meta.go
@@ -11,12 +11,12 @@
 package usecase
 
 import (
 	"context"
 
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // GetMetaPort is the interface used by this use case.
 type GetMetaPort interface {
 	// GetMeta retrieves just the meta data of a specific zettel.

Index: usecase/get_user.go
==================================================================
--- usecase/get_user.go
+++ usecase/get_user.go
@@ -14,13 +14,13 @@
 	"context"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Use case: return user identified by meta key ident.
 // ---------------------------------------------------
 

Index: usecase/get_zettel.go
==================================================================
--- usecase/get_zettel.go
+++ usecase/get_zettel.go
@@ -11,18 +11,18 @@
 package usecase
 
 import (
 	"context"
 
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
 )
 
 // GetZettelPort is the interface used by this use case.
 type GetZettelPort interface {
 	// GetZettel retrieves a specific zettel.
-	GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error)
+	GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error)
 }
 
 // GetZettel is the data for this use case.
 type GetZettel struct {
 	port GetZettelPort
@@ -32,8 +32,8 @@
 func NewGetZettel(port GetZettelPort) GetZettel {
 	return GetZettel{port: port}
 }
 
 // Run executes the use case.
-func (uc GetZettel) Run(ctx context.Context, zid id.Zid) (domain.Zettel, error) {
+func (uc GetZettel) Run(ctx context.Context, zid id.Zid) (zettel.Zettel, error) {
 	return uc.port.GetZettel(ctx, zid)
 }

Index: usecase/lists.go
==================================================================
--- usecase/lists.go
+++ usecase/lists.go
@@ -13,13 +13,13 @@
 import (
 	"context"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // ListMetaPort is the interface used by this use case.
 type ListMetaPort interface {
 	// SelectMeta returns all zettel metadata that match the selection criteria.

Index: usecase/order.go
==================================================================
--- usecase/order.go
+++ usecase/order.go
@@ -12,12 +12,12 @@
 
 import (
 	"context"
 
 	"zettelstore.de/z/collect"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // ZettelOrderPort is the interface used by this use case.
 type ZettelOrderPort interface {
 	// GetMeta retrieves just the meta data of a specific zettel.

Index: usecase/parse_zettel.go
==================================================================
--- usecase/parse_zettel.go
+++ usecase/parse_zettel.go
@@ -13,12 +13,12 @@
 import (
 	"context"
 
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/parser"
+	"zettelstore.de/z/zettel/id"
 )
 
 // ParseZettel is the data for this use case.
 type ParseZettel struct {
 	rtConfig  config.Config

Index: usecase/rename_zettel.go
==================================================================
--- usecase/rename_zettel.go
+++ usecase/rename_zettel.go
@@ -12,13 +12,13 @@
 
 import (
 	"context"
 
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/logger"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // RenameZettelPort is the interface used by this use case.
 type RenameZettelPort interface {
 	// GetMeta retrieves just the meta data of a specific zettel.

Index: usecase/unlinked_refs.go
==================================================================
--- usecase/unlinked_refs.go
+++ usecase/unlinked_refs.go
@@ -16,23 +16,23 @@
 	"unicode"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder/textenc"
 	"zettelstore.de/z/evaluator"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/query"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // UnlinkedReferencesPort is the interface used by this use case.
 type UnlinkedReferencesPort interface {
 	GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error)
-	GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error)
+	GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error)
 	SelectMeta(ctx context.Context, q *query.Query) ([]*meta.Meta, error)
 }
 
 // UnlinkedReferences is the data for this use case.
 type UnlinkedReferences struct {

Index: usecase/update_zettel.go
==================================================================
--- usecase/update_zettel.go
+++ usecase/update_zettel.go
@@ -13,23 +13,23 @@
 import (
 	"context"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/logger"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // UpdateZettelPort is the interface used by this use case.
 type UpdateZettelPort interface {
 	// GetZettel retrieves a specific zettel.
-	GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error)
+	GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error)
 
 	// UpdateZettel updates an existing zettel.
-	UpdateZettel(ctx context.Context, zettel domain.Zettel) error
+	UpdateZettel(ctx context.Context, zettel zettel.Zettel) error
 }
 
 // UpdateZettel is the data for this use case.
 type UpdateZettel struct {
 	log  *logger.Logger
@@ -40,11 +40,11 @@
 func NewUpdateZettel(log *logger.Logger, port UpdateZettelPort) UpdateZettel {
 	return UpdateZettel{log: log, port: port}
 }
 
 // Run executes the use case.
-func (uc *UpdateZettel) Run(ctx context.Context, zettel domain.Zettel, hasContent bool) error {
+func (uc *UpdateZettel) Run(ctx context.Context, zettel zettel.Zettel, hasContent bool) error {
 	m := zettel.Meta
 	oldZettel, err := uc.port.GetZettel(box.NoEnrichContext(ctx), m.Zid)
 	if err != nil {
 		return err
 	}

Index: web/adapter/api/api.go
==================================================================
--- web/adapter/api/api.go
+++ web/adapter/api/api.go
@@ -18,15 +18,15 @@
 	"time"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/web/adapter"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // API holds all data and methods for delivering API call results.
 type API struct {
 	log      *logger.Logger
@@ -64,11 +64,11 @@
 func (a *API) getAuthData(ctx context.Context) *server.AuthData {
 	return server.GetAuthData(ctx)
 }
 func (a *API) withAuth() bool { return a.authz.WithAuth() }
 func (a *API) getToken(ident *meta.Meta) ([]byte, error) {
-	return a.token.GetToken(ident, a.tokenLifetime, auth.KindJSON)
+	return a.token.GetToken(ident, a.tokenLifetime, auth.KindAPI)
 }
 
 func (a *API) reportUsecaseError(w http.ResponseWriter, err error) {
 	code, text := adapter.CodeMessageFromError(err)
 	if code == http.StatusInternalServerError {

Index: web/adapter/api/create_zettel.go
==================================================================
--- web/adapter/api/create_zettel.go
+++ web/adapter/api/create_zettel.go
@@ -13,24 +13,24 @@
 import (
 	"bytes"
 	"net/http"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
 	"zettelstore.de/z/web/content"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
 )
 
 // MakePostCreateZettelHandler creates a new HTTP handler to store content of
 // an existing zettel.
 func (a *API) MakePostCreateZettelHandler(createZettel *usecase.CreateZettel) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		q := r.URL.Query()
 		enc, encStr := getEncoding(r, q)
-		var zettel domain.Zettel
+		var zettel zettel.Zettel
 		var err error
 		switch enc {
 		case api.EncoderPlain:
 			zettel, err = buildZettelFromPlainData(r, id.Invalid)
 		case api.EncoderJson:

Index: web/adapter/api/delete_zettel.go
==================================================================
--- web/adapter/api/delete_zettel.go
+++ web/adapter/api/delete_zettel.go
@@ -11,12 +11,12 @@
 package api
 
 import (
 	"net/http"
 
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/usecase"
+	"zettelstore.de/z/zettel/id"
 )
 
 // MakeDeleteZettelHandler creates a new HTTP handler to delete a zettel.
 func (a *API) MakeDeleteZettelHandler(deleteZettel *usecase.DeleteZettel) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {

Index: web/adapter/api/get_order.go
==================================================================
--- web/adapter/api/get_order.go
+++ web/adapter/api/get_order.go
@@ -12,12 +12,12 @@
 
 import (
 	"net/http"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/usecase"
+	"zettelstore.de/z/zettel/id"
 )
 
 // MakeGetOrderHandler creates a new API handler to return zettel references
 // of a given zettel.
 func (a *API) MakeGetOrderHandler(zettelOrder usecase.ZettelOrder) http.HandlerFunc {

Index: web/adapter/api/get_unlinked_refs.go
==================================================================
--- web/adapter/api/get_unlinked_refs.go
+++ web/adapter/api/get_unlinked_refs.go
@@ -13,15 +13,15 @@
 import (
 	"bytes"
 	"net/http"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
 	"zettelstore.de/z/web/content"
+	"zettelstore.de/z/zettel/id"
 )
 
 // MakeListUnlinkedMetaHandler creates a new HTTP handler for the use case "list unlinked references".
 func (a *API) MakeListUnlinkedMetaHandler(getMeta usecase.GetMeta, unlinkedRefs usecase.UnlinkedReferences) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {

Index: web/adapter/api/get_zettel.go
==================================================================
--- web/adapter/api/get_zettel.go
+++ web/adapter/api/get_zettel.go
@@ -14,19 +14,22 @@
 	"bytes"
 	"context"
 	"fmt"
 	"net/http"
 
+	"codeberg.org/t73fde/sxpf"
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/encoder"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
 	"zettelstore.de/z/web/content"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // MakeGetZettelHandler creates a new HTTP handler to return a zettel in various encodings.
 func (a *API) MakeGetZettelHandler(getMeta usecase.GetMeta, getZettel usecase.GetZettel, parseZettel usecase.ParseZettel, evaluate usecase.Evaluate) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -41,10 +44,13 @@
 		ctx := r.Context()
 		switch enc, encStr := getEncoding(r, q); enc {
 		case api.EncoderPlain:
 			a.writePlainData(w, ctx, zid, part, getMeta, getZettel)
 
+		case api.EncoderData:
+			a.writeSzData(w, ctx, zid, part, getMeta, getZettel)
+
 		case api.EncoderJson:
 			a.writeJSONData(w, ctx, zid, part, getMeta, getZettel)
 
 		default:
 			var zn *ast.ZettelNode
@@ -112,10 +118,72 @@
 		return
 	}
 	err = writeBuffer(w, &buf, contentType)
 	a.log.IfErr(err).Zid(zid).Msg("Write Plain data")
 }
+
+func (a *API) writeSzData(w http.ResponseWriter, ctx context.Context, zid id.Zid, part partType, getMeta usecase.GetMeta, getZettel usecase.GetZettel) {
+	var obj sxpf.Object
+	switch part {
+	case partZettel:
+		z, err := getZettel.Run(ctx, zid)
+		if err != nil {
+			a.reportUsecaseError(w, err)
+			return
+		}
+		obj = zettel2sz(z, a.getRights(ctx, z.Meta))
+
+	case partMeta:
+		m, err := getMeta.Run(ctx, zid)
+		if err != nil {
+			a.reportUsecaseError(w, err)
+			return
+		}
+		obj = metaRights2sz(m, a.getRights(ctx, m))
+	}
+
+	var buf bytes.Buffer
+	_, err := sxpf.Print(&buf, obj)
+	if err != nil {
+		a.log.Fatal().Err(err).Zid(zid).Msg("Unable to store zettel/part in buffer")
+		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+		return
+	}
+
+	err = writeBuffer(w, &buf, content.PlainText)
+	a.log.IfErr(err).Zid(zid).Msg("Write data")
+}
+
+func zettel2sz(z zettel.Zettel, rights api.ZettelRights) sxpf.Object {
+	zContent, encoding := z.Content.Encode()
+	sf := sxpf.MakeMappedFactory()
+	return sxpf.MakeList(
+		sf.MustMake("zettel"),
+		sxpf.MakeList(sf.MustMake("id"), sxpf.MakeString(z.Meta.Zid.String())),
+		meta2sz(z.Meta, sf),
+		sxpf.MakeList(sf.MustMake("rights"), sxpf.Int64(int64(rights))),
+		sxpf.MakeList(sf.MustMake("encoding"), sxpf.MakeString(encoding)),
+		sxpf.MakeList(sf.MustMake("content"), sxpf.MakeString(zContent)),
+	)
+}
+func metaRights2sz(m *meta.Meta, rights api.ZettelRights) sxpf.Object {
+	sf := sxpf.MakeMappedFactory()
+	return sxpf.MakeList(
+		sf.MustMake("list"),
+		meta2sz(m, sf),
+		sxpf.MakeList(sf.MustMake("rights"), sxpf.Int64(int64(rights))),
+	)
+}
+func meta2sz(m *meta.Meta, sf sxpf.SymbolFactory) sxpf.Object {
+	result := sxpf.Nil().Cons(sf.MustMake("meta"))
+	curr := result
+	for _, p := range m.ComputedPairs() {
+		val := sxpf.MakeList(sf.MustMake(p.Key), sxpf.MakeString(p.Value))
+		curr = curr.AppendBang(val)
+	}
+	return result
+}
 
 func (a *API) writeJSONData(w http.ResponseWriter, ctx context.Context, zid id.Zid, part partType, getMeta usecase.GetMeta, getZettel usecase.GetZettel) {
 	var buf bytes.Buffer
 	var err error
 

DELETED web/adapter/api/get_zettel_context.go
Index: web/adapter/api/get_zettel_context.go
==================================================================
--- web/adapter/api/get_zettel_context.go
+++ web/adapter/api/get_zettel_context.go
@@ -1,50 +0,0 @@
-//-----------------------------------------------------------------------------
-// Copyright (c) 2020-present Detlef Stern
-//
-// This file is part of Zettelstore.
-//
-// Zettelstore is licensed under the latest version of the EUPL (European Union
-// Public License). Please see file LICENSE.txt for your rights and obligations
-// under this license.
-//-----------------------------------------------------------------------------
-
-package api
-
-import (
-	"net/http"
-
-	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/usecase"
-	"zettelstore.de/z/web/adapter"
-)
-
-// MakeZettelContextHandler creates a new HTTP handler for the use case "zettel context".
-func (a *API) MakeZettelContextHandler(getContext usecase.ZettelContext) http.HandlerFunc {
-	return func(w http.ResponseWriter, r *http.Request) {
-		zid, err := id.Parse(r.URL.Path[1:])
-		if err != nil {
-			http.NotFound(w, r)
-			return
-		}
-		q := r.URL.Query()
-		dir := adapter.GetZCDirection(q.Get(api.QueryKeyDir))
-		cost, ok := adapter.GetInteger(q, api.QueryKeyCost)
-		if !ok || cost < 0 {
-			cost = 17
-		}
-		limit, ok := adapter.GetInteger(q, api.QueryKeyLimit)
-		if !ok || limit < 0 {
-			limit = 200
-		}
-		ctx := r.Context()
-		metaList, err := getContext.Run(ctx, zid, dir, cost, limit)
-		if err != nil {
-			a.reportUsecaseError(w, err)
-			return
-		}
-
-		err = a.writeMetaList(ctx, w, metaList[0], metaList[1:])
-		a.log.IfErr(err).Zid(zid).Msg("Write Context")
-	}
-}

Index: web/adapter/api/json.go
==================================================================
--- web/adapter/api/json.go
+++ web/adapter/api/json.go
@@ -16,14 +16,14 @@
 	"encoding/json"
 	"io"
 	"net/http"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/web/content"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func encodeJSONData(w io.Writer, data interface{}) error {
 	enc := json.NewEncoder(w)
 	enc.SetEscapeHTML(false)
@@ -52,12 +52,12 @@
 	}
 
 	return writeBuffer(w, &buf, content.JSON)
 }
 
-func buildZettelFromJSONData(r *http.Request, zid id.Zid) (domain.Zettel, error) {
-	var zettel domain.Zettel
+func buildZettelFromJSONData(r *http.Request, zid id.Zid) (zettel.Zettel, error) {
+	var zettel zettel.Zettel
 	dec := json.NewDecoder(r.Body)
 	var zettelData api.ZettelDataJSON
 	if err := dec.Decode(&zettelData); err != nil {
 		return zettel, err
 	}

Index: web/adapter/api/login.go
==================================================================
--- web/adapter/api/login.go
+++ web/adapter/api/login.go
@@ -10,15 +10,15 @@
 
 package api
 
 import (
 	"bytes"
-	"encoding/json"
 	"net/http"
 	"time"
 
-	"zettelstore.de/c/api"
+	"codeberg.org/t73fde/sxpf"
+
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
 	"zettelstore.de/z/web/content"
 )
@@ -25,18 +25,18 @@
 
 // MakePostLoginHandler creates a new HTTP handler to authenticate the given user via API.
 func (a *API) MakePostLoginHandler(ucAuth *usecase.Authenticate) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		if !a.withAuth() {
-			err := a.writeJSONToken(w, "freeaccess", 24*366*10*time.Hour)
+			err := a.writeToken(w, "freeaccess", 24*366*10*time.Hour)
 			a.log.IfErr(err).Msg("Login/free")
 			return
 		}
 		var token []byte
 		if ident, cred := retrieveIdentCred(r); ident != "" {
 			var err error
-			token, err = ucAuth.Run(r.Context(), r, ident, cred, a.tokenLifetime, auth.KindJSON)
+			token, err = ucAuth.Run(r.Context(), r, ident, cred, a.tokenLifetime, auth.KindAPI)
 			if err != nil {
 				a.reportUsecaseError(w, err)
 				return
 			}
 		}
@@ -44,11 +44,11 @@
 			w.Header().Set("WWW-Authenticate", `Bearer realm="Default"`)
 			http.Error(w, "Authentication failed", http.StatusUnauthorized)
 			return
 		}
 
-		err := a.writeJSONToken(w, string(token), a.tokenLifetime)
+		err := a.writeToken(w, string(token), a.tokenLifetime)
 		a.log.IfErr(err).Msg("Login")
 	}
 }
 
 func retrieveIdentCred(r *http.Request) (string, string) {
@@ -59,33 +59,16 @@
 		return ident, cred
 	}
 	return "", ""
 }
 
-func (a *API) writeJSONToken(w http.ResponseWriter, token string, lifetime time.Duration) error {
-	var buf bytes.Buffer
-	je := json.NewEncoder(&buf)
-	err := je.Encode(api.AuthJSON{
-		Token:   token,
-		Type:    "Bearer",
-		Expires: int(lifetime / time.Second),
-	})
-	if err != nil {
-		a.log.Fatal().Err(err).Msg("Unable to store token in buffer")
-		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
-		return nil
-	}
-
-	return writeBuffer(w, &buf, content.JSON)
-}
-
 // MakeRenewAuthHandler creates a new HTTP handler to renew the authenticate of a user.
 func (a *API) MakeRenewAuthHandler() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		ctx := r.Context()
 		if !a.withAuth() {
-			err := a.writeJSONToken(w, "freeaccess", 24*366*10*time.Hour)
+			err := a.writeToken(w, "freeaccess", 24*366*10*time.Hour)
 			a.log.IfErr(err).Msg("Refresh/free")
 			return
 		}
 		authData := a.getAuthData(ctx)
 		if authData == nil || len(authData.Token) == 0 || authData.User == nil {
@@ -94,11 +77,11 @@
 		}
 		totalLifetime := authData.Expires.Sub(authData.Issued)
 		currentLifetime := authData.Now.Sub(authData.Issued)
 		// If we are in the first quarter of the tokens lifetime, return the token
 		if currentLifetime*4 < totalLifetime {
-			err := a.writeJSONToken(w, string(authData.Token), totalLifetime-currentLifetime)
+			err := a.writeToken(w, string(authData.Token), totalLifetime-currentLifetime)
 			a.log.IfErr(err).Msg("Write old token")
 			return
 		}
 
 		// Token is a little bit aged. Create a new one
@@ -105,9 +88,26 @@
 		token, err := a.getToken(authData.User)
 		if err != nil {
 			a.reportUsecaseError(w, err)
 			return
 		}
-		err = a.writeJSONToken(w, string(token), a.tokenLifetime)
+		err = a.writeToken(w, string(token), a.tokenLifetime)
 		a.log.IfErr(err).Msg("Write renewed token")
 	}
 }
+
+func (a *API) writeToken(w http.ResponseWriter, token string, lifetime time.Duration) error {
+	lst := sxpf.MakeList(
+		sxpf.MakeString("Bearer"),
+		sxpf.MakeString(token),
+		sxpf.Int64(int64(lifetime/time.Second)),
+	)
+	var buf bytes.Buffer
+	_, err := sxpf.Print(&buf, lst)
+	if err != nil {
+		a.log.Fatal().Err(err).Msg("Unable to store token in buffer")
+		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+		return nil
+	}
+
+	return writeBuffer(w, &buf, content.PlainText)
+}

Index: web/adapter/api/query.go
==================================================================
--- web/adapter/api/query.go
+++ web/adapter/api/query.go
@@ -17,15 +17,15 @@
 	"net/http"
 	"strconv"
 	"strings"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/query"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
 	"zettelstore.de/z/web/content"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // MakeQueryHandler creates a new HTTP handler to perform a query.
 func (a *API) MakeQueryHandler(listMeta usecase.ListMeta) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {

Index: web/adapter/api/rename_zettel.go
==================================================================
--- web/adapter/api/rename_zettel.go
+++ web/adapter/api/rename_zettel.go
@@ -13,12 +13,12 @@
 import (
 	"net/http"
 	"net/url"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/usecase"
+	"zettelstore.de/z/zettel/id"
 )
 
 // MakeRenameZettelHandler creates a new HTTP handler to update a zettel.
 func (a *API) MakeRenameZettelHandler(renameZettel *usecase.RenameZettel) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {

Index: web/adapter/api/request.go
==================================================================
--- web/adapter/api/request.go
+++ web/adapter/api/request.go
@@ -14,14 +14,14 @@
 	"io"
 	"net/http"
 	"net/url"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // getEncoding returns the data encoding selected by the caller.
 func getEncoding(r *http.Request, q url.Values) (api.EncodingEnum, string) {
 	encoding := q.Get(api.QueryKeyEncoding)
@@ -98,18 +98,18 @@
 		return ""
 	}
 	return p.String()
 }
 
-func buildZettelFromPlainData(r *http.Request, zid id.Zid) (domain.Zettel, error) {
+func buildZettelFromPlainData(r *http.Request, zid id.Zid) (zettel.Zettel, error) {
 	b, err := io.ReadAll(r.Body)
 	if err != nil {
-		return domain.Zettel{}, err
+		return zettel.Zettel{}, err
 	}
 	inp := input.NewInput(b)
 	m := meta.NewFromInput(zid, inp)
-	return domain.Zettel{
+	return zettel.Zettel{
 		Meta:    m,
-		Content: domain.NewContent(inp.Src[inp.Pos:]),
+		Content: zettel.NewContent(inp.Src[inp.Pos:]),
 	}, nil
 
 }

Index: web/adapter/api/update_zettel.go
==================================================================
--- web/adapter/api/update_zettel.go
+++ web/adapter/api/update_zettel.go
@@ -12,14 +12,14 @@
 
 import (
 	"net/http"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
 )
 
 // MakeUpdateZettelHandler creates a new HTTP handler to update a zettel.
 func (a *API) MakeUpdateZettelHandler(updateZettel *usecase.UpdateZettel) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -28,11 +28,11 @@
 			http.NotFound(w, r)
 			return
 		}
 
 		q := r.URL.Query()
-		var zettel domain.Zettel
+		var zettel zettel.Zettel
 		switch enc, _ := getEncoding(r, q); enc {
 		case api.EncoderPlain:
 			zettel, err = buildZettelFromPlainData(r, zid)
 		case api.EncoderJson:
 			zettel, err = buildZettelFromJSONData(r, zid)

Index: web/adapter/request.go
==================================================================
--- web/adapter/request.go
+++ web/adapter/request.go
@@ -15,14 +15,13 @@
 	"net/url"
 	"strconv"
 	"strings"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/query"
-	"zettelstore.de/z/usecase"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // GetCredentialsViaForm retrieves the authentication credentions from a form.
 func GetCredentialsViaForm(r *http.Request) (ident, cred string, ok bool) {
 	err := r.ParseForm()
@@ -37,21 +36,10 @@
 		return "", "", false
 	}
 	return ident, cred, true
 }
 
-// GetInteger returns the integer value of the named query key.
-func GetInteger(q url.Values, key string) (int, bool) {
-	s := q.Get(key)
-	if s != "" {
-		if val, err := strconv.Atoi(s); err == nil {
-			return val, true
-		}
-	}
-	return 0, false
-}
-
 // GetQuery retrieves the specified options from a query.
 func GetQuery(vals url.Values) (result *query.Query) {
 	if exprs, found := vals[api.QueryKeyQuery]; found {
 		result = query.Parse(strings.Join(exprs, " "))
 	}
@@ -64,21 +52,10 @@
 		}
 	}
 	return result
 }
 
-// GetZCDirection returns a direction value for a given string.
-func GetZCDirection(s string) usecase.ZettelContextDirection {
-	switch s {
-	case api.DirBackward:
-		return usecase.ZettelContextBackward
-	case api.DirForward:
-		return usecase.ZettelContextForward
-	}
-	return usecase.ZettelContextBoth
-}
-
 // AddUnlinkedRefsToQuery inspects metadata and enhances the given query to ignore
 // some zettel identifier.
 func AddUnlinkedRefsToQuery(q *query.Query, m *meta.Meta) *query.Query {
 	var sb strings.Builder
 	sb.WriteString(api.KeyID)

Index: web/adapter/webui/create_zettel.go
==================================================================
--- web/adapter/webui/create_zettel.go
+++ web/adapter/webui/create_zettel.go
@@ -12,22 +12,24 @@
 
 import (
 	"bytes"
 	"context"
 	"net/http"
+	"strings"
 
+	"codeberg.org/t73fde/sxpf"
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder/zmkenc"
 	"zettelstore.de/z/evaluator"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // MakeGetCreateZettelHandler creates a new HTTP handler to display the
 // HTML edit view for the various zettel creation methods.
 func (wui *WebUI) MakeGetCreateZettelHandler(
@@ -79,35 +81,46 @@
 }
 
 func (wui *WebUI) renderZettelForm(
 	ctx context.Context,
 	w http.ResponseWriter,
-	zettel domain.Zettel,
+	zettel zettel.Zettel,
 	title string,
 	formActionURL string,
 	roleData []string,
 	syntaxData []string,
 ) {
 	user := server.GetUser(ctx)
 	m := zettel.Meta
-	var base baseData
-	wui.makeBaseData(ctx, wui.rtConfig.Get(ctx, m, api.KeyLang), title, "", user, &base)
-	wui.renderTemplate(ctx, w, id.FormTemplateZid, &base, formZettelData{
-		Heading:       title,
-		FormActionURL: formActionURL,
-		MetaTitle:     m.GetDefault(api.KeyTitle, ""),
-		MetaTags:      m.GetDefault(api.KeyTags, ""),
-		MetaRole:      m.GetDefault(api.KeyRole, ""),
-		HasRoleData:   len(roleData) > 0,
-		RoleData:      roleData,
-		HasSyntaxData: len(syntaxData) > 0,
-		SyntaxData:    syntaxData,
-		MetaSyntax:    m.GetDefault(api.KeySyntax, ""),
-		MetaPairsRest: m.PairsRest(),
-		IsTextContent: !zettel.Content.IsBinary(),
-		Content:       zettel.Content.AsString(),
-	})
+
+	var sb strings.Builder
+	for _, p := range m.PairsRest() {
+		sb.WriteString(p.Key)
+		sb.WriteString(": ")
+		sb.WriteString(p.Value)
+		sb.WriteByte('\n')
+	}
+	env, err := wui.createRenderEnv(ctx, "form", wui.rtConfig.Get(ctx, nil, api.KeyLang), title, user)
+	rb := makeRenderBinder(wui.sf, env, err)
+	rb.bindString("heading", sxpf.MakeString(title))
+	rb.bindString("form-action-url", sxpf.MakeString(formActionURL))
+	rb.bindString("meta-title", sxpf.MakeString(m.GetDefault(api.KeyTitle, "")))
+	rb.bindString("meta-role", sxpf.MakeString(m.GetDefault(api.KeyRole, "")))
+	rb.bindString("meta-tags", sxpf.MakeString(m.GetDefault(api.KeyTags, "")))
+	rb.bindString("meta-syntax", sxpf.MakeString(m.GetDefault(api.KeySyntax, "")))
+	rb.bindString("role-data", makeStringList(roleData))
+	rb.bindString("syntax-data", makeStringList(syntaxData))
+	rb.bindString("meta", sxpf.MakeString(sb.String()))
+	if !zettel.Content.IsBinary() {
+		rb.bindString("content", sxpf.MakeString(zettel.Content.AsString()))
+	}
+	if rb.err == nil {
+		err = wui.renderSxnTemplate(ctx, w, id.FormTemplateZid, env)
+	}
+	if err != nil {
+		wui.reportError(ctx, w, err)
+	}
 }
 
 // MakePostCreateZettelHandler creates a new HTTP handler to store content of
 // an existing zettel.
 func (wui *WebUI) MakePostCreateZettelHandler(createZettel *usecase.CreateZettel) http.HandlerFunc {
@@ -165,10 +178,10 @@
 		m.Set(api.KeyTitle, q.Human())
 		m.Set(api.KeySyntax, api.ValueSyntaxZmk)
 		if qval := q.String(); qval != "" {
 			m.Set(api.KeyQuery, qval)
 		}
-		zettel := domain.Zettel{Meta: m, Content: domain.NewContent(zmkContent.Bytes())}
+		zettel := zettel.Zettel{Meta: m, Content: zettel.NewContent(zmkContent.Bytes())}
 		roleData, syntaxData := retrieveDataLists(ctx, ucListRoles, ucListSyntax)
 		wui.renderZettelForm(ctx, w, zettel, "Zettel from list", wui.createNewURL, roleData, syntaxData)
 	}
 }

Index: web/adapter/webui/delete_zettel.go
==================================================================
--- web/adapter/webui/delete_zettel.go
+++ web/adapter/webui/delete_zettel.go
@@ -11,18 +11,19 @@
 package webui
 
 import (
 	"net/http"
 
+	"codeberg.org/t73fde/sxpf"
 	"zettelstore.de/c/api"
 	"zettelstore.de/c/maps"
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/strfun"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // MakeGetDeleteZettelHandler creates a new HTTP handler to display the
 // HTML delete view of a zettel.
 func (wui *WebUI) MakeGetDeleteZettelHandler(getMeta usecase.GetMeta, getAllMeta usecase.GetAllMeta) http.HandlerFunc {
@@ -39,48 +40,77 @@
 			wui.reportError(ctx, w, err)
 			return
 		}
 		m := ms[0]
 
-		var shadowedBox string
-		var incomingLinks simpleLinks
-		if len(ms) > 1 {
-			shadowedBox = ms[1].GetDefault(api.KeyBoxNumber, "???")
-		} else {
-			getTextTitle := wui.makeGetTextTitle(ctx, getMeta)
-			incomingLinks = wui.encodeIncoming(m, getTextTitle)
-		}
-		uselessFiles := retrieveUselessFiles(m)
-
-		user := server.GetUser(ctx)
-		var base baseData
-		wui.makeBaseData(ctx, wui.rtConfig.Get(ctx, m, api.KeyLang), "Delete Zettel "+m.Zid.String(), "", user, &base)
-		wui.renderTemplate(ctx, w, id.DeleteTemplateZid, &base, struct {
-			Zid             string
-			MetaPairs       []meta.Pair
-			HasShadows      bool
-			ShadowedBox     string
-			Incoming        simpleLinks
-			HasUselessFiles bool
-			UselessFiles    []string
-		}{
-			Zid:             zid.String(),
-			MetaPairs:       m.ComputedPairs(),
-			HasShadows:      shadowedBox != "",
-			ShadowedBox:     shadowedBox,
-			Incoming:        incomingLinks,
-			HasUselessFiles: len(uselessFiles) > 0,
-			UselessFiles:    uselessFiles,
-		})
-	}
-}
-
-func retrieveUselessFiles(m *meta.Meta) []string {
-	if val, found := m.Get(api.KeyUselessFiles); found {
-		return []string{val}
-	}
-	return nil
+		user := server.GetUser(ctx)
+		env, err := wui.createRenderEnv(
+			ctx, "delete",
+			wui.rtConfig.Get(ctx, nil, api.KeyLang), "Delete Zettel "+m.Zid.String(), user)
+		rb := makeRenderBinder(wui.sf, env, err)
+		rb.bindString("zid", sxpf.MakeString(m.Zid.String()))
+		if len(ms) > 1 {
+			rb.bindString("shadowed-box", sxpf.MakeString(ms[1].GetDefault(api.KeyBoxNumber, "???")))
+			rb.bindString("incoming", nil)
+		} else {
+			rb.bindString("shadowed-box", nil)
+			rb.bindString("incoming", wui.encodeIncoming(m, wui.makeGetTextTitle(ctx, getMeta)))
+		}
+		rb.bindString("useless", retrieveUselessFiles(m))
+		rb.bindString("meta-pairs", makeMetaPairs(m))
+		if rb.err == nil {
+			err = wui.renderSxnTemplate(ctx, w, id.DeleteTemplateZid, env)
+		}
+		if err != nil {
+			wui.reportError(ctx, w, err)
+		}
+	}
+}
+
+func retrieveUselessFiles(m *meta.Meta) *sxpf.List {
+	if val, found := m.Get(api.KeyUselessFiles); found {
+		return sxpf.Cons(sxpf.MakeString(val), nil)
+	}
+	return nil
+}
+
+func (wui *WebUI) encodeIncoming(m *meta.Meta, getTextTitle getTextTitleFunc) *sxpf.List {
+	zidMap := make(strfun.Set)
+	addListValues(zidMap, m, api.KeyBackward)
+	for _, kd := range meta.GetSortedKeyDescriptions() {
+		inverseKey := kd.Inverse
+		if inverseKey == "" {
+			continue
+		}
+		ikd := meta.GetDescription(inverseKey)
+		switch ikd.Type {
+		case meta.TypeID:
+			if val, ok := m.Get(inverseKey); ok {
+				zidMap.Set(val)
+			}
+		case meta.TypeIDSet:
+			addListValues(zidMap, m, inverseKey)
+		}
+	}
+	return wui.zidLinksSxn(maps.Keys(zidMap), getTextTitle)
+}
+
+func addListValues(zidMap strfun.Set, m *meta.Meta, key string) {
+	if values, ok := m.GetList(key); ok {
+		for _, val := range values {
+			zidMap.Set(val)
+		}
+	}
+}
+
+func makeMetaPairs(m *meta.Meta) *sxpf.List {
+	sentinel := sxpf.Cons(nil, nil)
+	curr := sentinel
+	for _, p := range m.ComputedPairs() {
+		curr = curr.AppendBang(sxpf.Cons(sxpf.MakeString(p.Key), sxpf.MakeString(p.Value)))
+	}
+	return sentinel.Tail()
 }
 
 // MakePostDeleteZettelHandler creates a new HTTP handler to delete a zettel.
 func (wui *WebUI) MakePostDeleteZettelHandler(deleteZettel *usecase.DeleteZettel) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -96,34 +126,5 @@
 			return
 		}
 		wui.redirectFound(w, r, wui.NewURLBuilder('/'))
 	}
 }
-
-func (wui *WebUI) encodeIncoming(m *meta.Meta, getTextTitle getTextTitleFunc) simpleLinks {
-	zidMap := make(strfun.Set)
-	addListValues(zidMap, m, api.KeyBackward)
-	for _, kd := range meta.GetSortedKeyDescriptions() {
-		inverseKey := kd.Inverse
-		if inverseKey == "" {
-			continue
-		}
-		ikd := meta.GetDescription(inverseKey)
-		switch ikd.Type {
-		case meta.TypeID:
-			if val, ok := m.Get(inverseKey); ok {
-				zidMap.Set(val)
-			}
-		case meta.TypeIDSet:
-			addListValues(zidMap, m, inverseKey)
-		}
-	}
-	return createSimpleLinks(wui.encodeZidLinks(maps.Keys(zidMap), getTextTitle))
-}
-
-func addListValues(zidMap strfun.Set, m *meta.Meta, key string) {
-	if values, ok := m.GetList(key); ok {
-		for _, val := range values {
-			zidMap.Set(val)
-		}
-	}
-}

Index: web/adapter/webui/edit_zettel.go
==================================================================
--- web/adapter/webui/edit_zettel.go
+++ web/adapter/webui/edit_zettel.go
@@ -13,13 +13,13 @@
 import (
 	"net/http"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
+	"zettelstore.de/z/zettel/id"
 )
 
 // MakeEditGetZettelHandler creates a new HTTP handler to display the
 // HTML edit view of a zettel.
 func (wui *WebUI) MakeEditGetZettelHandler(getZettel usecase.GetZettel, ucListRoles usecase.ListRoles, ucListSyntax usecase.ListSyntax) http.HandlerFunc {

Index: web/adapter/webui/forms.go
==================================================================
--- web/adapter/webui/forms.go
+++ web/adapter/webui/forms.go
@@ -18,47 +18,31 @@
 	"regexp"
 	"strings"
 	"unicode"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/input"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/web/content"
-)
-
-type formZettelData struct {
-	Heading       string
-	FormActionURL string
-	MetaTitle     string
-	MetaRole      string
-	HasRoleData   bool
-	RoleData      []string
-	HasSyntaxData bool
-	SyntaxData    []string
-	MetaTags      string
-	MetaSyntax    string
-	MetaPairsRest []meta.Pair
-	IsTextContent bool
-	Content       string
-}
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
+)
 
 var (
 	bsCRLF = []byte{'\r', '\n'}
 	bsLF   = []byte{'\n'}
 )
 
 var errMissingContent = errors.New("missing zettel content")
 
-func parseZettelForm(r *http.Request, zid id.Zid) (bool, domain.Zettel, error) {
+func parseZettelForm(r *http.Request, zid id.Zid) (bool, zettel.Zettel, error) {
 	maxRequestSize := kernel.Main.GetConfig(kernel.WebService, kernel.WebMaxRequestSize).(int64)
 	err := r.ParseMultipartForm(maxRequestSize)
 	if err != nil {
-		return false, domain.Zettel{}, err
+		return false, zettel.Zettel{}, err
 	}
 	_, doSave := r.Form["save"]
 
 	var m *meta.Meta
 	if postMeta, ok := trimmedFormValue(r, "meta"); ok {
@@ -81,20 +65,20 @@
 	if postSyntax, ok := trimmedFormValue(r, "syntax"); ok {
 		m.Set(api.KeySyntax, meta.RemoveNonGraphic(postSyntax))
 	}
 
 	if data := textContent(r); data != nil {
-		return doSave, domain.Zettel{Meta: m, Content: domain.NewContent(data)}, nil
+		return doSave, zettel.Zettel{Meta: m, Content: zettel.NewContent(data)}, nil
 	}
 	if data, m2 := uploadedContent(r, m); data != nil {
-		return doSave, domain.Zettel{Meta: m2, Content: domain.NewContent(data)}, nil
+		return doSave, zettel.Zettel{Meta: m2, Content: zettel.NewContent(data)}, nil
 	}
 
 	if allowEmptyContent(m) {
-		return doSave, domain.Zettel{Meta: m, Content: domain.NewContent(nil)}, nil
+		return doSave, zettel.Zettel{Meta: m, Content: zettel.NewContent(nil)}, nil
 	}
-	return doSave, domain.Zettel{Meta: m, Content: domain.NewContent(nil)}, errMissingContent
+	return doSave, zettel.Zettel{Meta: m, Content: zettel.NewContent(nil)}, errMissingContent
 }
 
 func trimmedFormValue(r *http.Request, key string) (string, bool) {
 	if values, ok := r.PostForm[key]; ok && len(values) > 0 {
 		value := strings.TrimSpace(values[0])

Index: web/adapter/webui/get_info.go
==================================================================
--- web/adapter/webui/get_info.go
+++ web/adapter/webui/get_info.go
@@ -19,17 +19,17 @@
 	"codeberg.org/t73fde/sxpf"
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/collect"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/encoder"
 	"zettelstore.de/z/evaluator"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/id"
 )
 
 type metaDataInfo struct {
 	Key   string
 	Value string
@@ -107,14 +107,10 @@
 			wui.reportError(ctx, w, err)
 			return
 		}
 
 		shadowLinks := getShadowLinks(ctx, zid, getAllMeta)
-		endnotes, err := enc.BlocksString(&ast.BlockSlice{})
-		if err != nil {
-			endnotes = ""
-		}
 
 		user := server.GetUser(ctx)
 		canCreate := wui.canCreate(ctx, user)
 		apiZid := api.ZettelID(zid.String())
 		var base baseData
@@ -147,15 +143,14 @@
 			QueryKeyPhrase string
 			EvalMatrix     []matrixLine
 			ParseMatrix    []matrixLine
 			HasShadowLinks bool
 			ShadowLinks    []string
-			Endnotes       string
 		}{
 			Zid:            zid.String(),
 			WebURL:         wui.NewURLBuilder('h').SetZid(apiZid).String(),
-			ContextURL:     wui.NewURLBuilder('k').SetZid(apiZid).String(),
+			ContextURL:     wui.NewURLBuilder('h').AppendQuery(api.ContextDirective + " " + zid.String()).String(),
 			CanWrite:       wui.canWrite(ctx, user, zn.Meta, zn.Content),
 			EditURL:        wui.NewURLBuilder('e').SetZid(apiZid).String(),
 			CanCopy:        canCreate && !zn.Content.IsBinary(),
 			CopyURL:        wui.NewURLBuilder('c').SetZid(apiZid).AppendKVQuery(queryKeyAction, valueActionCopy).String(),
 			CanVersion:     canCreate,
@@ -175,14 +170,13 @@
 			ExtNewWindow:   htmlAttrNewWindow(len(extLinks) > 0),
 			UnLinksContent: unlinkedContent,
 			UnLinksPhrase:  phrase,
 			QueryKeyPhrase: api.QueryKeyPhrase,
 			EvalMatrix:     wui.infoAPIMatrix(zid, false),
-			ParseMatrix:    wui.infoAPIMatrixPlain(zid),
+			ParseMatrix:    wui.infoAPIMatrixParsed(zid),
 			HasShadowLinks: len(shadowLinks) > 0,
 			ShadowLinks:    shadowLinks,
-			Endnotes:       endnotes,
 		})
 	}
 }
 
 type localLink struct {
@@ -235,30 +229,41 @@
 		matrix = append(matrix, matrixLine{part, row})
 	}
 	return matrix
 }
 
-func (wui *WebUI) infoAPIMatrixPlain(zid id.Zid) []matrixLine {
+func (wui *WebUI) infoAPIMatrixParsed(zid id.Zid) []matrixLine {
 	matrix := wui.infoAPIMatrix(zid, true)
 	apiZid := api.ZettelID(zid.String())
 
-	// Append plain and JSON format
+	// Append plain and data format
 	u := wui.NewURLBuilder('z').SetZid(apiZid)
 	for i, part := range getParts() {
 		u.AppendKVQuery(api.QueryKeyPart, part)
 		matrix[i].Elements = append(matrix[i].Elements, simpleLink{"plain", u.AttrString()})
 		u.ClearQuery()
 	}
 
+	u.AppendKVQuery(api.QueryKeyEncoding, api.EncodingData)
+	u.AppendKVQuery(api.QueryKeyPart, api.PartZettel)
+	matrix[0].Elements = append(matrix[0].Elements, simpleLink{"data", u.AttrString()})
+
+	u.ClearQuery()
+	u.AppendKVQuery(api.QueryKeyEncoding, api.EncodingData)
+	u.AppendKVQuery(api.QueryKeyPart, api.PartMeta)
+	matrix[1].Elements = append(matrix[1].Elements, simpleLink{"data", u.AttrString()})
+
+	u.ClearQuery()
 	u.AppendKVQuery(api.QueryKeyEncoding, api.EncodingJson)
 	u.AppendKVQuery(api.QueryKeyPart, api.PartZettel)
 	matrix[0].Elements = append(matrix[0].Elements, simpleLink{"json", u.AttrString()})
 
 	u.ClearQuery()
 	u.AppendKVQuery(api.QueryKeyEncoding, api.EncodingJson)
 	u.AppendKVQuery(api.QueryKeyPart, api.PartMeta)
 	matrix[1].Elements = append(matrix[1].Elements, simpleLink{"json", u.AttrString()})
+
 	return matrix
 }
 
 func getParts() []string {
 	return []string{api.PartZettel, api.PartMeta, api.PartContent}

Index: web/adapter/webui/get_zettel.go
==================================================================
--- web/adapter/webui/get_zettel.go
+++ web/adapter/webui/get_zettel.go
@@ -9,20 +9,21 @@
 //-----------------------------------------------------------------------------
 
 package webui
 
 import (
+	"context"
 	"net/http"
-	"strings"
 
+	"codeberg.org/t73fde/sxpf"
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // MakeGetHTMLZettelHandler creates a new HTTP handler for the use case "get zettel".
 func (wui *WebUI) MakeGetHTMLZettelHandler(evaluate *usecase.Evaluate, getMeta usecase.GetMeta) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -33,162 +34,151 @@
 			return
 		}
 
 		q := r.URL.Query()
 		zn, err := evaluate.Run(ctx, zid, q.Get(api.KeySyntax))
-
 		if err != nil {
 			wui.reportError(ctx, w, err)
 			return
 		}
 
 		enc := wui.getSimpleHTMLEncoder()
-		htmlContent, err := enc.BlocksString(&zn.Ast)
-		if err != nil {
-			wui.reportError(ctx, w, err)
-			return
-		}
-		var roleCSSURL string
-		cssZid, err := wui.retrieveCSSZidFromRole(ctx, *zn.InhMeta)
-		if err != nil {
-			wui.reportError(ctx, w, err)
-			return
-		}
-		if cssZid != id.Invalid {
-			roleCSSURL = wui.NewURLBuilder('z').SetZid(api.ZettelID(cssZid.String())).String()
-		}
-		user := server.GetUser(ctx)
-		roleText := zn.Meta.GetDefault(api.KeyRole, "")
-		canCreate := wui.canCreate(ctx, user)
-		getTextTitle := wui.makeGetTextTitle(ctx, getMeta)
-		extURL, hasExtURL := wui.formatURLFromMeta(zn.Meta, api.KeyURL)
-		folgeLinks := createSimpleLinks(wui.encodeZettelLinks(zn.InhMeta, api.KeyFolge, getTextTitle))
-		backLinks := createSimpleLinks(wui.encodeZettelLinks(zn.InhMeta, api.KeyBack, getTextTitle))
-		successorLinks := createSimpleLinks(wui.encodeZettelLinks(zn.InhMeta, api.KeySuccessors, getTextTitle))
-		apiZid := api.ZettelID(zid.String())
-
-		var base baseData
-		title := parser.NormalizedSpacedText(zn.InhMeta.GetTitle())
-		wui.makeBaseData(ctx, wui.rtConfig.Get(ctx, zn.InhMeta, api.KeyLang), title, roleCSSURL, user, &base)
-		base.MetaHeader = enc.MetaString(zn.InhMeta, createEvalMetadataFunc(ctx, evaluate))
-		wui.renderTemplate(ctx, w, id.ZettelTemplateZid, &base, struct {
-			Heading         string
-			RoleCSS         string
-			CanWrite        bool
-			EditURL         string
-			Zid             string
-			InfoURL         string
-			RoleText        string
-			RoleURL         string
-			Tags            simpleLinks
-			CanCopy         bool
-			CopyURL         string
-			CanVersion      bool
-			VersionURL      string
-			CanFolge        bool
-			FolgeURL        string
-			PredecessorRefs string
-			PrecursorRefs   string
-			HasExtURL       bool
-			ExtURL          string
-			Author          string
-			Content         string
-			NeedBottomNav   bool
-			FolgeLinks      simpleLinks
-			BackLinks       simpleLinks
-			SuccessorLinks  simpleLinks
-		}{
-			Heading:         title,
-			RoleCSS:         roleCSSURL,
-			CanWrite:        wui.canWrite(ctx, user, zn.Meta, zn.Content),
-			EditURL:         wui.NewURLBuilder('e').SetZid(apiZid).String(),
-			Zid:             zid.String(),
-			InfoURL:         wui.NewURLBuilder('i').SetZid(apiZid).String(),
-			RoleText:        roleText,
-			RoleURL:         wui.NewURLBuilder('h').AppendQuery(api.KeyRole + api.SearchOperatorHas + roleText).String(),
-			Tags:            createSimpleLinks(wui.buildTagInfos(zn.Meta)),
-			CanCopy:         canCreate && !zn.Content.IsBinary(),
-			CopyURL:         wui.NewURLBuilder('c').SetZid(apiZid).AppendKVQuery(queryKeyAction, valueActionCopy).String(),
-			CanVersion:      canCreate,
-			VersionURL:      wui.NewURLBuilder('c').SetZid(apiZid).AppendKVQuery(queryKeyAction, valueActionVersion).String(),
-			CanFolge:        canCreate,
-			FolgeURL:        wui.NewURLBuilder('c').SetZid(apiZid).AppendKVQuery(queryKeyAction, valueActionFolge).String(),
-			PredecessorRefs: wui.encodeIdentifierSet(zn.InhMeta, api.KeyPredecessor, getTextTitle),
-			PrecursorRefs:   wui.encodeIdentifierSet(zn.InhMeta, api.KeyPrecursor, getTextTitle),
-			ExtURL:          extURL,
-			HasExtURL:       hasExtURL,
-			Author:          zn.Meta.GetDefault(api.KeyAuthor, ""),
-			Content:         htmlContent,
-			NeedBottomNav:   folgeLinks.Has || backLinks.Has || successorLinks.Has,
-			FolgeLinks:      folgeLinks,
-			BackLinks:       backLinks,
-			SuccessorLinks:  successorLinks,
-		})
-	}
-}
-
-func (wui *WebUI) formatURLFromMeta(m *meta.Meta, key string) (string, bool) {
-	val, found := m.Get(key)
-	if !found {
-		return "", false
-	}
-	if val == "" {
-		return "", false
-	}
-
-	var sb strings.Builder
-	_, err := wui.htmlGen.WriteHTML(&sb, wui.transformURL(val))
-	if err != nil {
-		return "", false
-	}
-	return sb.String(), true
-}
-
-func (wui *WebUI) buildTagInfos(m *meta.Meta) []simpleLink {
-	var tagInfos []simpleLink
-	if tags, ok := m.GetList(api.KeyTags); ok {
-		ub := wui.NewURLBuilder('h')
-		tagInfos = make([]simpleLink, len(tags))
-		for i, tag := range tags {
-			tagInfos[i] = simpleLink{Text: tag, URL: ub.AppendQuery(api.KeyTags + api.SearchOperatorHas + tag).String()}
-			ub.ClearQuery()
-		}
-	}
-	return tagInfos
-}
-
-func (wui *WebUI) encodeIdentifierSet(m *meta.Meta, key string, getTextTitle getTextTitleFunc) string {
-	if value, ok := m.Get(key); ok {
-		sval := wui.transformIdentifierSet(meta.ListFromValue(value), getTextTitle)
-		var sb strings.Builder
-		wui.htmlGen.WriteHTML(&sb, sval)
-		return sb.String()
-	}
-	return ""
-}
-
-func (wui *WebUI) encodeZettelLinks(m *meta.Meta, key string, getTextTitle getTextTitleFunc) []simpleLink {
-	values, ok := m.GetList(key)
-	if !ok || len(values) == 0 {
-		return nil
-	}
-	return wui.encodeZidLinks(values, getTextTitle)
-}
-
-func (wui *WebUI) encodeZidLinks(values []string, getTextTitle getTextTitleFunc) []simpleLink {
-	result := make([]simpleLink, 0, len(values))
-	for _, val := range values {
+		metaObj := enc.MetaSxn(zn.InhMeta, createEvalMetadataFunc(ctx, evaluate))
+		content, endnotes, err := enc.BlocksSxn(&zn.Ast)
+		if err != nil {
+			wui.reportError(ctx, w, err)
+			return
+		}
+
+		cssRoleURL, err := wui.getCSSRoleURL(ctx, zn.InhMeta)
+		if err != nil {
+			wui.reportError(ctx, w, err)
+			return
+		}
+
+		user := server.GetUser(ctx)
+		apiZid := api.ZettelID(zid.String())
+		canCreate := wui.canCreate(ctx, user)
+		getTextTitle := wui.makeGetTextTitle(ctx, getMeta)
+
+		title := parser.NormalizedSpacedText(zn.InhMeta.GetTitle())
+		env, err := wui.createRenderEnv(ctx, "zettel", wui.rtConfig.Get(ctx, zn.InhMeta, api.KeyLang), title, user)
+		rb := makeRenderBinder(wui.sf, env, err)
+		rb.bindSymbol(wui.symMetaHeader, metaObj)
+		rb.bindString("css-role-url", sxpf.MakeString(cssRoleURL))
+		rb.bindString("heading", sxpf.MakeString(title))
+		rb.bindString("can-write", sxpf.MakeBoolean(wui.canWrite(ctx, user, zn.Meta, zn.Content)))
+		rb.bindString("edit-url", sxpf.MakeString(wui.NewURLBuilder('e').SetZid(apiZid).String()))
+		rb.bindString("info-url", sxpf.MakeString(wui.NewURLBuilder('i').SetZid(apiZid).String()))
+		rb.bindString("role-url",
+			sxpf.MakeString(wui.NewURLBuilder('h').AppendQuery(api.KeyRole+api.SearchOperatorHas+zn.Meta.GetDefault(api.KeyRole, "")).String()))
+		rb.bindString("tag-refs", wui.transformTagSet(api.KeyTags, meta.ListFromValue(zn.InhMeta.GetDefault(api.KeyTags, ""))))
+		rb.bindString("can-copy", sxpf.Boolean(canCreate && !zn.Content.IsBinary()))
+		rb.bindString("copy-url", sxpf.MakeString(wui.NewURLBuilder('c').SetZid(apiZid).AppendKVQuery(queryKeyAction, valueActionCopy).String()))
+		rb.bindString("can-version", sxpf.Boolean(canCreate))
+		rb.bindString("version-url", sxpf.MakeString(wui.NewURLBuilder('c').SetZid(apiZid).AppendKVQuery(queryKeyAction, valueActionVersion).String()))
+		rb.bindString("can-folge", sxpf.Boolean(canCreate))
+		rb.bindString("folge-url", sxpf.MakeString(wui.NewURLBuilder('c').SetZid(apiZid).AppendKVQuery(queryKeyAction, valueActionFolge).String()))
+		rb.bindString("predecessor-refs", wui.identifierSetAsLinks(zn.InhMeta, api.KeyPredecessor, getTextTitle))
+		rb.bindString("precursor-refs", wui.identifierSetAsLinks(zn.InhMeta, api.KeyPrecursor, getTextTitle))
+		rb.bindString("superior-refs", wui.identifierSetAsLinks(zn.InhMeta, api.KeySuperior, getTextTitle))
+		rb.bindString("ext-url", wui.urlFromMeta(zn.InhMeta, api.KeyURL))
+		rb.bindString("content", content)
+		rb.bindString("endnotes", endnotes)
+		rb.bindString("folge-links", wui.zettelLinksSxn(zn.InhMeta, api.KeyFolge, getTextTitle))
+		rb.bindString("subordinate-links", wui.zettelLinksSxn(zn.InhMeta, api.KeySubordinates, getTextTitle))
+		rb.bindString("back-links", wui.zettelLinksSxn(zn.InhMeta, api.KeyBack, getTextTitle))
+		rb.bindString("successor-links", wui.zettelLinksSxn(zn.InhMeta, api.KeySuccessors, getTextTitle))
+		if rb.err == nil {
+			err = bindMeta(zn.InhMeta, wui.sf, env)
+		}
+		if err == nil {
+			err = wui.renderSxnTemplate(ctx, w, id.ZettelTemplateZid, env)
+		}
+		if err != nil {
+			wui.reportError(ctx, w, err)
+		}
+	}
+}
+
+func (wui *WebUI) getCSSRoleURL(ctx context.Context, m *meta.Meta) (string, error) {
+	cssZid, err := wui.retrieveCSSZidFromRole(ctx, m)
+	if err != nil {
+		return "", err
+	}
+	if cssZid == id.Invalid {
+		return "", nil
+	}
+	return wui.NewURLBuilder('z').SetZid(api.ZettelID(cssZid.String())).String(), nil
+}
+
+func (wui *WebUI) identifierSetAsLinks(m *meta.Meta, key string, getTextTitle getTextTitleFunc) *sxpf.List {
+	if values, ok := m.GetList(key); ok {
+		return wui.transformIdentifierSet(values, getTextTitle)
+	}
+	return sxpf.Nil()
+}
+
+func (wui *WebUI) urlFromMeta(m *meta.Meta, key string) sxpf.Object {
+	val, found := m.Get(key)
+	if !found || val == "" {
+		return sxpf.Nil()
+	}
+	return wui.transformURL(val)
+}
+
+func (wui *WebUI) zettelLinksSxn(m *meta.Meta, key string, getTextTitle getTextTitleFunc) *sxpf.List {
+	values, ok := m.GetList(key)
+	if !ok || len(values) == 0 {
+		return nil
+	}
+	return wui.zidLinksSxn(values, getTextTitle)
+}
+
+func (wui *WebUI) zidLinksSxn(values []string, getTextTitle getTextTitleFunc) (lst *sxpf.List) {
+	for i := len(values) - 1; i >= 0; i-- {
+		val := values[i]
 		zid, err := id.Parse(val)
 		if err != nil {
 			continue
 		}
 		if title, found := getTextTitle(zid); found > 0 {
-			url := wui.NewURLBuilder('h').SetZid(api.ZettelID(zid.String())).String()
+			url := sxpf.MakeString(wui.NewURLBuilder('h').SetZid(api.ZettelID(zid.String())).String())
 			if title == "" {
-				result = append(result, simpleLink{Text: val, URL: url})
+				lst = lst.Cons(sxpf.Cons(sxpf.MakeString(val), url))
 			} else {
-				result = append(result, simpleLink{Text: title, URL: url})
+				lst = lst.Cons(sxpf.Cons(sxpf.MakeString(title), url))
+			}
+		}
+	}
+	return lst
+}
+
+func bindMeta(m *meta.Meta, sf sxpf.SymbolFactory, env sxpf.Environment) error {
+	for _, p := range m.ComputedPairs() {
+		keySym, err := sf.Make("meta-" + p.Key)
+		if err != nil {
+			return err
+		}
+		if kt := meta.Type(p.Key); kt.IsSet {
+			values := meta.ListFromValue(p.Value)
+			if len(values) == 0 {
+				continue
+			}
+			sxValues := make([]sxpf.Object, len(values))
+			for i, v := range values {
+				sxValues[i] = sxpf.MakeString(v)
 			}
+			err = env.Bind(keySym, sxpf.MakeList(sxValues...))
+		} else {
+			err = env.Bind(keySym, sxpf.MakeString(p.Value))
+		}
+		if err != nil {
+			return err
 		}
 	}
-	return result
+	symZid, err := sf.Make("zid")
+	if err != nil {
+		return err
+	}
+	return env.Bind(symZid, sxpf.MakeString(m.Zid.String()))
 }

Index: web/adapter/webui/home.go
==================================================================
--- web/adapter/webui/home.go
+++ web/adapter/webui/home.go
@@ -16,13 +16,13 @@
 	"net/http"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type getRootStore interface {
 	// GetMeta retrieves just the meta data of a specific zettel.
 	GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error)

Index: web/adapter/webui/htmlgen.go
==================================================================
--- web/adapter/webui/htmlgen.go
+++ web/adapter/webui/htmlgen.go
@@ -14,30 +14,31 @@
 	"net/url"
 	"strings"
 
 	"codeberg.org/t73fde/sxhtml"
 	"codeberg.org/t73fde/sxpf"
+	"codeberg.org/t73fde/sxpf/eval"
 	"zettelstore.de/c/api"
 	"zettelstore.de/c/attrs"
 	"zettelstore.de/c/maps"
-	"zettelstore.de/c/sexpr"
 	"zettelstore.de/c/shtml"
+	"zettelstore.de/c/sz"
 	"zettelstore.de/z/ast"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/encoder"
-	"zettelstore.de/z/encoder/sexprenc"
+	"zettelstore.de/z/encoder/szenc"
 	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // Builder allows to build new URLs for the web service.
 type urlBuilder interface {
 	GetURLPrefix() string
 	NewURLBuilder(key byte) *api.URLBuilder
 }
 
 type htmlGenerator struct {
-	tx    *sexprenc.Transformer
+	tx    *szenc.Transformer
 	th    *shtml.Transformer
 	symAt *sxpf.Symbol
 }
 
 func (wui *WebUI) createGenerator(builder urlBuilder) *htmlGenerator {
@@ -50,27 +51,27 @@
 	symClass := th.Make("class")
 	symTarget := th.Make("target")
 	symRel := th.Make("rel")
 
 	findA := func(obj sxpf.Object) (attr, assoc, rest *sxpf.List) {
-		lst, ok := obj.(*sxpf.List)
+		lst, ok := sxpf.GetList(obj)
 		if !ok || !symA.IsEqual(lst.Car()) {
 			return nil, nil, nil
 		}
 		rest = lst.Tail()
 		if rest == nil {
 			return nil, nil, nil
 		}
 		objA := rest.Car()
-		attr, ok = objA.(*sxpf.List)
+		attr, ok = sxpf.GetList(objA)
 		if !ok || !symAt.IsEqual(attr.Car()) {
 			return nil, nil, nil
 		}
 		return attr, attr.Tail(), rest.Tail()
 	}
-	linkZettel := func(_ sxpf.Environment, args *sxpf.List, prevFn sxpf.Callable) sxpf.Object {
-		obj, err := prevFn.Call(nil, args)
+	linkZettel := func(args []sxpf.Object, prevFn eval.Callable) sxpf.Object {
+		obj, err := prevFn.Call(nil, nil, args)
 		if err != nil {
 			return sxpf.Nil()
 		}
 		attr, assoc, rest := findA(obj)
 		if attr == nil {
@@ -79,11 +80,11 @@
 
 		hrefP := assoc.Assoc(symHref)
 		if hrefP == nil {
 			return obj
 		}
-		href, ok := hrefP.Cdr().(sxpf.String)
+		href, ok := sxpf.GetString(hrefP.Cdr())
 		if !ok {
 			return obj
 		}
 		zid, fragment, hasFragment := strings.Cut(href.String(), "#")
 		u := builder.NewURLBuilder('h').SetZid(api.ZettelID(zid))
@@ -93,14 +94,14 @@
 		assoc = assoc.Cons(sxpf.Cons(symHref, sxpf.MakeString(u.String())))
 		return rest.Cons(assoc.Cons(symAt)).Cons(symA)
 	}
 
 	th.SetRebinder(func(te *shtml.TransformEnv) {
-		te.Rebind(sexpr.NameSymLinkZettel, linkZettel)
-		te.Rebind(sexpr.NameSymLinkFound, linkZettel)
-		te.Rebind(sexpr.NameSymLinkBased, func(_ sxpf.Environment, args *sxpf.List, prevFn sxpf.Callable) sxpf.Object {
-			obj, err := prevFn.Call(nil, args)
+		te.Rebind(sz.NameSymLinkZettel, linkZettel)
+		te.Rebind(sz.NameSymLinkFound, linkZettel)
+		te.Rebind(sz.NameSymLinkBased, func(args []sxpf.Object, prevFn eval.Callable) sxpf.Object {
+			obj, err := prevFn.Call(nil, nil, args)
 			if err != nil {
 				return sxpf.Nil()
 			}
 			attr, assoc, rest := findA(obj)
 			if attr == nil {
@@ -108,20 +109,20 @@
 			}
 			hrefP := assoc.Assoc(symHref)
 			if hrefP == nil {
 				return obj
 			}
-			href, ok := hrefP.Cdr().(sxpf.String)
+			href, ok := sxpf.GetString(hrefP.Cdr())
 			if !ok {
 				return obj
 			}
 			u := builder.NewURLBuilder('/').SetRawLocal(href.String())
 			assoc = assoc.Cons(sxpf.Cons(symHref, sxpf.MakeString(u.String())))
 			return rest.Cons(assoc.Cons(symAt)).Cons(symA)
 		})
-		te.Rebind(sexpr.NameSymLinkQuery, func(_ sxpf.Environment, args *sxpf.List, prevFn sxpf.Callable) sxpf.Object {
-			obj, err := prevFn.Call(nil, args)
+		te.Rebind(sz.NameSymLinkQuery, func(args []sxpf.Object, prevFn eval.Callable) sxpf.Object {
+			obj, err := prevFn.Call(nil, nil, args)
 			if err != nil {
 				return sxpf.Nil()
 			}
 			attr, assoc, rest := findA(obj)
 			if attr == nil {
@@ -129,11 +130,11 @@
 			}
 			hrefP := assoc.Assoc(symHref)
 			if hrefP == nil {
 				return obj
 			}
-			href, ok := hrefP.Cdr().(sxpf.String)
+			href, ok := sxpf.GetString(hrefP.Cdr())
 			if !ok {
 				return obj
 			}
 			ur, err := url.Parse(href.String())
 			if err != nil {
@@ -145,12 +146,12 @@
 			}
 			u := builder.NewURLBuilder('h').AppendQuery(q)
 			assoc = assoc.Cons(sxpf.Cons(symHref, sxpf.MakeString(u.String())))
 			return rest.Cons(assoc.Cons(symAt)).Cons(symA)
 		})
-		te.Rebind(sexpr.NameSymLinkExternal, func(_ sxpf.Environment, args *sxpf.List, prevFn sxpf.Callable) sxpf.Object {
-			obj, err := prevFn.Call(nil, args)
+		te.Rebind(sz.NameSymLinkExternal, func(args []sxpf.Object, prevFn eval.Callable) sxpf.Object {
+			obj, err := prevFn.Call(nil, nil, args)
 			if err != nil {
 				return sxpf.Nil()
 			}
 			attr, assoc, rest := findA(obj)
 			if attr == nil {
@@ -159,29 +160,29 @@
 			assoc = assoc.Cons(sxpf.Cons(symClass, sxpf.MakeString("external"))).
 				Cons(sxpf.Cons(symTarget, sxpf.MakeString("_blank"))).
 				Cons(sxpf.Cons(symRel, sxpf.MakeString("noopener noreferrer")))
 			return rest.Cons(assoc.Cons(symAt)).Cons(symA)
 		})
-		te.Rebind(sexpr.NameSymEmbed, func(_ sxpf.Environment, args *sxpf.List, prevFn sxpf.Callable) sxpf.Object {
-			obj, err := prevFn.Call(nil, args)
+		te.Rebind(sz.NameSymEmbed, func(args []sxpf.Object, prevFn eval.Callable) sxpf.Object {
+			obj, err := prevFn.Call(nil, nil, args)
 			if err != nil {
 				return sxpf.Nil()
 			}
-			lst, ok := obj.(*sxpf.List)
+			lst, ok := sxpf.GetList(obj)
 			if !ok || !symImg.IsEqual(lst.Car()) {
 				return obj
 			}
-			attr, ok := lst.Tail().Car().(*sxpf.List)
+			attr, ok := sxpf.GetList(lst.Tail().Car())
 			if !ok || !symAt.IsEqual(attr.Car()) {
 				return obj
 			}
 			symSrc := th.Make("src")
 			srcP := attr.Tail().Assoc(symSrc)
 			if srcP == nil {
 				return obj
 			}
-			src, ok := srcP.Cdr().(sxpf.String)
+			src, ok := sxpf.GetString(srcP.Cdr())
 			if !ok {
 				return obj
 			}
 			zid := api.ZettelID(src)
 			if !zid.IsValid() {
@@ -192,26 +193,29 @@
 			return lst.Tail().Tail().Cons(imgAttr).Cons(symImg)
 		})
 	})
 
 	return &htmlGenerator{
-		tx:    sexprenc.NewTransformer(),
+		tx:    szenc.NewTransformer(),
 		th:    th,
 		symAt: symAt,
 	}
 }
 
+// SetUnique sets a prefix to make several HTML ids unique.
+func (g *htmlGenerator) SetUnique(s string) *htmlGenerator { g.th.SetUnique(s); return g }
+
 var mapMetaKey = map[string]string{
 	api.KeyCopyright: "copyright",
 	api.KeyLicense:   "license",
 }
 
-func (g *htmlGenerator) MetaString(m *meta.Meta, evalMeta encoder.EvalMetaFunc) string {
+func (g *htmlGenerator) MetaSxn(m *meta.Meta, evalMeta encoder.EvalMetaFunc) *sxpf.List {
 	tm := g.tx.GetMeta(m, evalMeta)
 	hm, err := g.th.Transform(tm)
 	if err != nil {
-		return ""
+		return nil
 	}
 
 	ignore := strfun.NewSet(api.KeyTitle, api.KeyLang)
 	metaMap := make(map[string]*sxpf.List, m.Length())
 	if tags, ok := m.Get(api.KeyTags); ok {
@@ -218,51 +222,54 @@
 		metaMap[api.KeyTags] = g.transformMetaTags(tags)
 		ignore.Set(api.KeyTags)
 	}
 
 	for elem := hm; elem != nil; elem = elem.Tail() {
-		mlst, ok := elem.Car().(*sxpf.List)
+		mlst, ok := sxpf.GetList(elem.Car())
 		if !ok {
 			continue
 		}
-		att, ok := mlst.Tail().Car().(*sxpf.List)
+		att, ok := sxpf.GetList(mlst.Tail().Car())
 		if !ok {
 			continue
 		}
 		if !att.Car().IsEqual(g.symAt) {
 			continue
 		}
 		a := make(attrs.Attributes, 32)
 		for aelem := att.Tail(); aelem != nil; aelem = aelem.Tail() {
-			if p, ok2 := aelem.Car().(*sxpf.List); ok2 {
+			if p, ok2 := sxpf.GetList(aelem.Car()); ok2 {
 				key := p.Car()
 				val := p.Cdr()
-				if tail, ok3 := val.(*sxpf.List); ok3 {
+				if tail, ok3 := sxpf.GetList(val); ok3 {
 					val = tail.Car()
 				}
 				a = a.Set(key.String(), val.String())
 			}
 		}
 		name, found := a.Get("name")
 		if !found || ignore.Has(name) {
 			continue
 		}
-		var newName string
-		if altName, found2 := mapMetaKey[name]; found2 {
-			newName = altName
-		} else {
-			newName = "zs-" + name
+
+		newName, found := mapMetaKey[name]
+		if !found {
+			continue
 		}
 		a = a.Set("name", newName)
 		metaMap[newName] = g.th.TransformMeta(a)
 	}
 	result := sxpf.Nil()
 	keys := maps.Keys(metaMap)
 	for i := len(keys) - 1; i >= 0; i-- {
 		result = result.Cons(metaMap[keys[i]])
 	}
+	return result
+}
 
+func (g *htmlGenerator) MetaString(m *meta.Meta, evalMeta encoder.EvalMetaFunc) string {
+	result := g.MetaSxn(m, evalMeta)
 	var sb strings.Builder
 	gen := sxhtml.NewGenerator(sxpf.FindSymbolFactory(result))
 	_, _ = gen.WriteListHTML(&sb, result)
 	return sb.String()
 }
@@ -278,17 +285,29 @@
 	if len(metaTags) == 0 {
 		return sxpf.Nil()
 	}
 	return g.th.TransformMeta(attrs.Attributes{"name": "keywords", "content": metaTags})
 }
+
+func (g *htmlGenerator) BlocksSxn(bs *ast.BlockSlice) (content, endnotes *sxpf.List, _ error) {
+	if bs == nil || len(*bs) == 0 {
+		return nil, nil, nil
+	}
+	sx := g.tx.GetSz(bs)
+	sh, err := g.th.Transform(sx)
+	if err != nil {
+		return nil, nil, err
+	}
+	return sh, g.th.Endnotes(), nil
+}
 
 // BlocksString encodes a block slice.
 func (g *htmlGenerator) BlocksString(bs *ast.BlockSlice) (string, error) {
 	if bs == nil || len(*bs) == 0 {
 		return "", nil
 	}
-	sx := g.tx.GetSexpr(bs)
+	sx := g.tx.GetSz(bs)
 	sh, err := g.th.Transform(sx)
 	if err != nil {
 		return "", err
 	}
 	var sb strings.Builder
@@ -305,11 +324,11 @@
 // InlinesSxHTML returns an inline slice, encoded as a SxHTML object.
 func (g *htmlGenerator) InlinesSxHTML(is *ast.InlineSlice) *sxpf.List {
 	if is == nil || len(*is) == 0 {
 		return sxpf.Nil()
 	}
-	sx := g.tx.GetSexpr(is)
+	sx := g.tx.GetSz(is)
 	sh, err := g.th.Transform(sx)
 	if err != nil {
 		return sxpf.Nil()
 	}
 	return sh

Index: web/adapter/webui/htmlmeta.go
==================================================================
--- web/adapter/webui/htmlmeta.go
+++ web/adapter/webui/htmlmeta.go
@@ -20,14 +20,14 @@
 	"codeberg.org/t73fde/sxhtml"
 	"codeberg.org/t73fde/sxpf"
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/ast"
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/usecase"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 func (wui *WebUI) writeHTMLMetaValue(
 	key, value string,
 	getTextTitle getTextTitleFunc,
@@ -80,20 +80,20 @@
 		ub := wui.NewURLBuilder('h').SetZid(api.ZettelID(zid.String()))
 		attrs := sxpf.Nil()
 		if title != "" {
 			attrs = attrs.Cons(sxpf.Cons(wui.sf.MustMake("title"), sxpf.MakeString(title)))
 		}
-		attrs = attrs.Cons(sxpf.Cons(wui.sf.MustMake("href"), sxpf.MakeString(ub.String()))).Cons(wui.sf.MustMake(sxhtml.NameSymAttr))
-		return sxpf.Nil().Cons(sxpf.MakeString(zid.String())).Cons(attrs).Cons(wui.sf.MustMake("a"))
+		attrs = attrs.Cons(sxpf.Cons(wui.symHref, sxpf.MakeString(ub.String()))).Cons(wui.symAttr)
+		return sxpf.Nil().Cons(sxpf.MakeString(zid.String())).Cons(attrs).Cons(wui.symA)
 	case found == 0:
 		return sxpf.Nil().Cons(text).Cons(wui.sf.MustMake("s"))
 	default: // case found < 0:
 		return text
 	}
 }
 
-func (wui *WebUI) transformIdentifierSet(vals []string, getTextTitle getTextTitleFunc) sxpf.Object {
+func (wui *WebUI) transformIdentifierSet(vals []string, getTextTitle getTextTitleFunc) *sxpf.List {
 	if len(vals) == 0 {
 		return sxpf.Nil()
 	}
 	space := sxpf.MakeString(" ")
 	text := make([]sxpf.Object, 0, 2*len(vals))
@@ -101,11 +101,11 @@
 		text = append(text, space, wui.transformIdentifier(val, getTextTitle))
 	}
 	return sxpf.MakeList(text[1:]...).Cons(wui.sf.MustMake("span"))
 }
 
-func (wui *WebUI) transformTagSet(key string, tags []string) sxpf.Object {
+func (wui *WebUI) transformTagSet(key string, tags []string) *sxpf.List {
 	if len(tags) == 0 {
 		return sxpf.Nil()
 	}
 	space := sxpf.MakeString(" ")
 	text := make([]sxpf.Object, 0, 2*len(tags))
@@ -130,14 +130,14 @@
 	text := sxpf.MakeString(val)
 	u, err := url.Parse(val)
 	if err == nil {
 		if us := u.String(); us != "" {
 			return sxpf.MakeList(
-				wui.sf.MustMake("a"),
+				wui.symA,
 				sxpf.MakeList(
-					wui.sf.MustMake(sxhtml.NameSymAttr),
-					sxpf.Cons(wui.sf.MustMake("href"), sxpf.MakeString(val)),
+					wui.symAttr,
+					sxpf.Cons(wui.symHref, sxpf.MakeString(val)),
 					sxpf.Cons(wui.sf.MustMake("target"), sxpf.MakeString("_blank")),
 					sxpf.Cons(wui.sf.MustMake("rel"), sxpf.MakeString("noopener noreferrer")),
 				),
 				text,
 			)
@@ -160,16 +160,16 @@
 		text = append(text, space, wui.transformWord(key, tag))
 	}
 	return sxpf.MakeList(text[1:]...).Cons(wui.sf.MustMake("span"))
 }
 
-func (wui *WebUI) transformLink(key, value, text string) sxpf.Object {
+func (wui *WebUI) transformLink(key, value, text string) *sxpf.List {
 	return sxpf.MakeList(
-		wui.sf.MustMake("a"),
+		wui.symA,
 		sxpf.MakeList(
-			wui.sf.MustMake(sxhtml.NameSymAttr),
-			sxpf.Cons(wui.sf.MustMake("href"), sxpf.MakeString(wui.NewURLBuilder('h').AppendQuery(key+api.SearchOperatorHas+value).String())),
+			wui.symAttr,
+			sxpf.Cons(wui.symHref, sxpf.MakeString(wui.NewURLBuilder('h').AppendQuery(key+api.SearchOperatorHas+value).String())),
 		),
 		sxpf.MakeString(text),
 	)
 }
 

Index: web/adapter/webui/lists.go
==================================================================
--- web/adapter/webui/lists.go
+++ web/adapter/webui/lists.go
@@ -12,33 +12,34 @@
 
 import (
 	"context"
 	"io"
 	"net/http"
-	"net/url"
 	"strings"
 
+	"codeberg.org/t73fde/sxpf"
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/ast"
 	"zettelstore.de/z/encoding/atom"
 	"zettelstore.de/z/encoding/rss"
 	"zettelstore.de/z/encoding/xml"
 	"zettelstore.de/z/evaluator"
 	"zettelstore.de/z/query"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // MakeListHTMLMetaHandler creates a HTTP handler for rendering the list of zettel as HTML.
-func (wui *WebUI) MakeListHTMLMetaHandler(listMeta usecase.ListMeta, evaluate *usecase.Evaluate) http.HandlerFunc {
+func (wui *WebUI) MakeListHTMLMetaHandler(listMeta usecase.ListMeta) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		q := adapter.GetQuery(r.URL.Query())
+		q = q.SetDeterministic()
 		ctx := r.Context()
-		metaList, err := listMeta.Run(box.NoEnrichQuery(ctx, q), q)
+		metaList, err := listMeta.Run(ctx, q)
 		if err != nil {
 			wui.reportError(ctx, w, err)
 			return
 		}
 		if actions := q.Actions(); len(actions) > 0 {
@@ -49,45 +50,49 @@
 			case "RSS":
 				wui.renderRSS(ctx, w, q, metaList)
 				return
 			}
 		}
-		bns := evaluate.RunBlockNode(ctx, evaluator.QueryAction(ctx, q, metaList, wui.rtConfig))
-		enc := wui.getSimpleHTMLEncoder()
-		htmlContent, err := enc.BlocksString(&bns)
-		if err != nil {
-			wui.reportError(ctx, w, err)
-			return
+		var content, endnotes *sxpf.List
+		if bn := evaluator.QueryAction(ctx, q, metaList, wui.rtConfig); bn != nil {
+			enc := wui.getSimpleHTMLEncoder()
+			content, endnotes, err = enc.BlocksSxn(&ast.BlockSlice{bn})
+			if err != nil {
+				wui.reportError(ctx, w, err)
+				return
+			}
 		}
 		seed, found := q.GetSeed()
 		if !found {
 			seed = 0
 		}
+
 		user := server.GetUser(ctx)
-		var base baseData
-		wui.makeBaseData(ctx, wui.rtConfig.Get(ctx, nil, api.KeyLang), wui.rtConfig.GetSiteName(), "", user, &base)
-		wui.renderTemplate(ctx, w, id.ListTemplateZid, &base, struct {
-			Title         string
-			SearchURL     string
-			QueryValue    string
-			QueryKeyQuery string
-			Content       string
-			CanCreate     bool
-			CreateURL     string
-			QueryKeySeed  string
-			Seed          int
-		}{
-			Title:         wui.listTitleQuery(q),
-			SearchURL:     base.SearchURL,
-			QueryValue:    q.String(),
-			QueryKeyQuery: base.QueryKeyQuery,
-			Content:       htmlContent,
-			CanCreate:     wui.canCreate(ctx, user),
-			CreateURL:     base.CreateNewURL,
-			QueryKeySeed:  base.QueryKeySeed,
-			Seed:          seed,
-		})
+		env, err := wui.createRenderEnv(
+			ctx, "list",
+			wui.rtConfig.Get(ctx, nil, api.KeyLang),
+			wui.rtConfig.GetSiteName(), user)
+		rb := makeRenderBinder(wui.sf, env, err)
+		if q == nil {
+			rb.bindString("heading", sxpf.MakeString(wui.rtConfig.GetSiteName()))
+		} else {
+			var sb strings.Builder
+			q.PrintHuman(&sb)
+			rb.bindString("heading", sxpf.MakeString(sb.String()))
+		}
+		rb.bindString("query-value", sxpf.MakeString(q.String()))
+		rb.bindString("content", content)
+		rb.bindString("endnotes", endnotes)
+		rb.bindString("can-create", sxpf.MakeBoolean(wui.canCreate(ctx, user)))
+		rb.bindString("create-url", sxpf.MakeString(wui.createNewURL))
+		rb.bindString("seed", sxpf.Int64(seed))
+		if rb.err == nil {
+			err = wui.renderSxnTemplate(ctx, w, id.ListTemplateZid, env)
+		}
+		if err != nil {
+			wui.reportError(ctx, w, err)
+		}
 	}
 }
 
 func (wui *WebUI) renderRSS(ctx context.Context, w http.ResponseWriter, q *query.Query, ml []*meta.Meta) {
 	var rssConfig rss.Configuration
@@ -124,80 +129,5 @@
 	}
 	if err != nil {
 		wui.log.IfErr(err).Msg("unable to write Atom data")
 	}
 }
-
-// MakeZettelContextHandler creates a new HTTP handler for the use case "zettel context".
-func (wui *WebUI) MakeZettelContextHandler(getContext usecase.ZettelContext, evaluate *usecase.Evaluate) http.HandlerFunc {
-	return func(w http.ResponseWriter, r *http.Request) {
-		ctx := r.Context()
-		zid, err := id.Parse(r.URL.Path[1:])
-		if err != nil {
-			wui.reportError(ctx, w, box.ErrNotFound)
-			return
-		}
-		q := r.URL.Query()
-		dir := adapter.GetZCDirection(q.Get(api.QueryKeyDir))
-		cost := getIntParameter(q, api.QueryKeyCost, 17)
-		limit := getIntParameter(q, api.QueryKeyLimit, 200)
-		metaList, err := getContext.Run(ctx, zid, dir, cost, limit)
-		if err != nil {
-			wui.reportError(ctx, w, err)
-			return
-		}
-		bns := evaluate.RunBlockNode(ctx, evaluator.QueryAction(ctx, nil, metaList, wui.rtConfig))
-		enc := wui.getSimpleHTMLEncoder()
-		htmlContent, err := enc.BlocksString(&bns)
-		if err != nil {
-			wui.reportError(ctx, w, err)
-			return
-		}
-		apiZid := api.ZettelID(zid.String())
-		costs := []string{"2", "3", "5", "8", "13", "21", "34", "55", "89"}
-		costLinks := make([]simpleLink, len(costs))
-		costURL := wui.NewURLBuilder('k').SetZid(apiZid)
-		for i, cost := range costs {
-			costURL.ClearQuery()
-			switch dir {
-			case usecase.ZettelContextBackward:
-				costURL.AppendKVQuery(api.QueryKeyDir, api.DirBackward)
-			case usecase.ZettelContextForward:
-				costURL.AppendKVQuery(api.QueryKeyDir, api.DirForward)
-			}
-			costURL.AppendKVQuery(api.QueryKeyCost, cost)
-			costLinks[i].Text = cost
-			costLinks[i].URL = costURL.String()
-		}
-		var base baseData
-		user := server.GetUser(ctx)
-		wui.makeBaseData(ctx, wui.rtConfig.Get(ctx, nil, api.KeyLang), wui.rtConfig.GetSiteName(), "", user, &base)
-		wui.renderTemplate(ctx, w, id.ContextTemplateZid, &base, struct {
-			Title   string
-			InfoURL string
-			Costs   []simpleLink
-			Content string
-		}{
-			Title:   "Zettel Context",
-			InfoURL: wui.NewURLBuilder('i').SetZid(apiZid).String(),
-			Costs:   costLinks,
-			Content: htmlContent,
-		})
-	}
-}
-
-func getIntParameter(q url.Values, key string, minValue int) int {
-	val, ok := adapter.GetInteger(q, key)
-	if !ok || val < 0 {
-		return minValue
-	}
-	return val
-}
-
-func (wui *WebUI) listTitleQuery(q *query.Query) string {
-	if q == nil {
-		return wui.rtConfig.GetSiteName()
-	}
-	var sb strings.Builder
-	q.PrintHuman(&sb)
-	return sb.String()
-}

Index: web/adapter/webui/login.go
==================================================================
--- web/adapter/webui/login.go
+++ web/adapter/webui/login.go
@@ -12,15 +12,16 @@
 
 import (
 	"context"
 	"net/http"
 
+	"codeberg.org/t73fde/sxpf"
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/auth"
-	"zettelstore.de/z/domain/id"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
+	"zettelstore.de/z/zettel/id"
 )
 
 // MakeGetLoginOutHandler creates a new HTTP handler to display the HTML login view,
 // or to execute a logout.
 func (wui *WebUI) MakeGetLoginOutHandler() http.HandlerFunc {
@@ -34,19 +35,20 @@
 		wui.renderLoginForm(wui.clearToken(r.Context(), w), w, false)
 	}
 }
 
 func (wui *WebUI) renderLoginForm(ctx context.Context, w http.ResponseWriter, retry bool) {
-	var base baseData
-	wui.makeBaseData(ctx, wui.rtConfig.Get(ctx, nil, api.KeyLang), "Login", "", nil, &base)
-	wui.renderTemplate(ctx, w, id.LoginTemplateZid, &base, struct {
-		Title string
-		Retry bool
-	}{
-		Title: base.Title,
-		Retry: retry,
-	})
+	env, err := wui.createRenderEnv(ctx, "login", wui.rtConfig.Get(ctx, nil, api.KeyLang), "Login", nil)
+	rb := makeRenderBinder(wui.sf, env, err)
+	rb.bindString("heading", sxpf.MakeString("Login"))
+	rb.bindString("retry", sxpf.MakeBoolean(retry))
+	if rb.err == nil {
+		err = wui.renderSxnTemplate(ctx, w, id.LoginTemplateZid, env)
+	}
+	if err != nil {
+		wui.reportError(ctx, w, err)
+	}
 }
 
 // MakePostLoginHandler creates a new HTTP handler to authenticate the given user.
 func (wui *WebUI) MakePostLoginHandler(ucAuth *usecase.Authenticate) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -58,11 +60,11 @@
 		ident, cred, ok := adapter.GetCredentialsViaForm(r)
 		if !ok {
 			wui.reportError(ctx, w, adapter.NewErrBadRequest("Unable to read login form"))
 			return
 		}
-		token, err := ucAuth.Run(ctx, r, ident, cred, wui.tokenLifetime, auth.KindHTML)
+		token, err := ucAuth.Run(ctx, r, ident, cred, wui.tokenLifetime, auth.KindwebUI)
 		if err != nil {
 			wui.reportError(ctx, w, err)
 			return
 		}
 		if token == nil {

Index: web/adapter/webui/rename_zettel.go
==================================================================
--- web/adapter/webui/rename_zettel.go
+++ web/adapter/webui/rename_zettel.go
@@ -13,17 +13,17 @@
 import (
 	"fmt"
 	"net/http"
 	"strings"
 
+	"codeberg.org/t73fde/sxpf"
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/box"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/id"
 )
 
 // MakeGetRenameZettelHandler creates a new HTTP handler to display the
 // HTML rename view of a zettel.
 func (wui *WebUI) MakeGetRenameZettelHandler(getMeta usecase.GetMeta) http.HandlerFunc {
@@ -39,29 +39,25 @@
 		if err != nil {
 			wui.reportError(ctx, w, err)
 			return
 		}
 
-		getTextTitle := wui.makeGetTextTitle(ctx, getMeta)
-		uselessFiles := retrieveUselessFiles(m)
-
 		user := server.GetUser(ctx)
-		var base baseData
-		wui.makeBaseData(ctx, wui.rtConfig.Get(ctx, m, api.KeyLang), "Rename Zettel "+zid.String(), "", user, &base)
-		wui.renderTemplate(ctx, w, id.RenameTemplateZid, &base, struct {
-			Zid             string
-			MetaPairs       []meta.Pair
-			Incoming        simpleLinks
-			HasUselessFiles bool
-			UselessFiles    []string
-		}{
-			Zid:             zid.String(),
-			MetaPairs:       m.ComputedPairs(),
-			Incoming:        wui.encodeIncoming(m, getTextTitle),
-			HasUselessFiles: len(uselessFiles) > 0,
-			UselessFiles:    uselessFiles,
-		})
+		env, err := wui.createRenderEnv(
+			ctx, "rename",
+			wui.rtConfig.Get(ctx, nil, api.KeyLang), "Rename Zettel "+m.Zid.String(), user)
+		rb := makeRenderBinder(wui.sf, env, err)
+		rb.bindString("zid", sxpf.MakeString(m.Zid.String()))
+		rb.bindString("incoming", wui.encodeIncoming(m, wui.makeGetTextTitle(ctx, getMeta)))
+		rb.bindString("useless", retrieveUselessFiles(m))
+		rb.bindString("meta-pairs", makeMetaPairs(m))
+		if rb.err == nil {
+			err = wui.renderSxnTemplate(ctx, w, id.RenameTemplateZid, env)
+		}
+		if err != nil {
+			wui.reportError(ctx, w, err)
+		}
 	}
 }
 
 // MakePostRenameZettelHandler creates a new HTTP handler to rename an existing zettel.
 func (wui *WebUI) MakePostRenameZettelHandler(renameZettel *usecase.RenameZettel) http.HandlerFunc {

ADDED   web/adapter/webui/template.go
Index: web/adapter/webui/template.go
==================================================================
--- web/adapter/webui/template.go
+++ web/adapter/webui/template.go
@@ -0,0 +1,308 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package webui
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"net/http"
+
+	"codeberg.org/t73fde/sxhtml"
+	"codeberg.org/t73fde/sxpf"
+	"codeberg.org/t73fde/sxpf/builtins"
+	"codeberg.org/t73fde/sxpf/builtins/binding"
+	"codeberg.org/t73fde/sxpf/builtins/boolean"
+	"codeberg.org/t73fde/sxpf/builtins/callable"
+	"codeberg.org/t73fde/sxpf/builtins/cond"
+	"codeberg.org/t73fde/sxpf/builtins/env"
+	"codeberg.org/t73fde/sxpf/builtins/list"
+	"codeberg.org/t73fde/sxpf/builtins/quote"
+	"codeberg.org/t73fde/sxpf/eval"
+	"codeberg.org/t73fde/sxpf/reader"
+	"zettelstore.de/c/api"
+	"zettelstore.de/z/box"
+	"zettelstore.de/z/collect"
+	"zettelstore.de/z/config"
+	"zettelstore.de/z/parser"
+	"zettelstore.de/z/web/adapter"
+	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
+)
+
+func (wui *WebUI) createRenderEngine() *eval.Engine {
+	root := sxpf.MakeRootEnvironment()
+	engine := eval.MakeEngine(wui.sf, root, eval.MakeDefaultParser(), eval.MakeSimpleExecutor())
+	quote.InstallQuoteSyntax(root, wui.symQuote)
+	quote.InstallQuasiQuoteSyntax(root, wui.symQQ, wui.symUQ, wui.symUQS)
+	engine.BindSyntax("if", cond.IfS)
+	engine.BindSyntax("and", boolean.AndS)
+	engine.BindSyntax("or", boolean.OrS)
+	engine.BindSyntax("lambda", callable.LambdaS)
+	engine.BindSyntax("let", binding.LetS)
+	engine.BindBuiltinEEA("bound?", env.BoundP)
+	engine.BindBuiltinEEA("map", callable.Map)
+	engine.BindBuiltinA("list", list.List)
+	engine.BindBuiltinA("pair-to-href", wui.sxnPairToHref)
+	engine.BindBuiltinA("pair-to-href-li", wui.sxnPairToHrefLi)
+	engine.BindBuiltinA("pairs-to-dl", wui.sxnPairsToDl)
+	return engine
+}
+
+func (wui *WebUI) sxnPairToHref(args []sxpf.Object) (sxpf.Object, error) {
+	err := builtins.CheckArgs(args, 1, 1)
+	pair, err := builtins.GetList(err, args, 0)
+	if err != nil {
+		return nil, err
+	}
+	href := sxpf.MakeList(
+		wui.symA,
+		sxpf.MakeList(wui.symAttr, sxpf.Cons(wui.symHref, pair.Cdr())),
+		pair.Car(),
+	)
+	return href, nil
+}
+func (wui *WebUI) sxnPairToHrefLi(args []sxpf.Object) (sxpf.Object, error) {
+	href, err := wui.sxnPairToHref(args)
+	if err != nil {
+		return nil, err
+	}
+	return sxpf.MakeList(wui.symLi, href), nil
+}
+func (wui *WebUI) sxnPairsToDl(args []sxpf.Object) (sxpf.Object, error) {
+	err := builtins.CheckArgs(args, 1, 1)
+	pairs, err := builtins.GetList(err, args, 0)
+	if err != nil {
+		return nil, err
+	}
+	dl := sxpf.Cons(wui.symDl, nil)
+	curr := dl
+	for node := pairs; node != nil; node = node.Tail() {
+		if pair, isPair := sxpf.GetList(node.Car()); isPair {
+			curr = curr.AppendBang(sxpf.MakeList(wui.symDt, pair.Car()))
+			curr = curr.AppendBang(sxpf.MakeList(wui.symDd, pair.Cdr()))
+		}
+	}
+	return dl, nil
+}
+
+// createRenderEnv creates a new environment and populates it with all relevant data for the base template.
+func (wui *WebUI) createRenderEnv(ctx context.Context, name, lang, title string, user *meta.Meta) (sxpf.Environment, error) {
+	userIsValid, userZettelURL, userIdent := wui.getUserRenderData(user)
+	env := sxpf.MakeChildEnvironment(wui.engine.RootEnvironment(), name, 128)
+	rb := makeRenderBinder(wui.sf, env, nil)
+	rb.bindString("lang", sxpf.MakeString(lang))
+	rb.bindString("css-base-url", sxpf.MakeString(wui.cssBaseURL))
+	rb.bindString("css-user-url", sxpf.MakeString(wui.cssUserURL))
+	rb.bindString("css-role-url", sxpf.MakeString(""))
+	rb.bindString("title", sxpf.MakeString(title))
+	rb.bindString("home-url", sxpf.MakeString(wui.homeURL))
+	rb.bindString("with-auth", sxpf.MakeBoolean(wui.withAuth))
+	rb.bindString("user-is-valid", sxpf.MakeBoolean(userIsValid))
+	rb.bindString("user-zettel-url", sxpf.MakeString(userZettelURL))
+	rb.bindString("user-ident", sxpf.MakeString(userIdent))
+	rb.bindString("login-url", sxpf.MakeString(wui.loginURL))
+	rb.bindString("logout-url", sxpf.MakeString(wui.logoutURL))
+	rb.bindString("list-zettel-url", sxpf.MakeString(wui.listZettelURL))
+	rb.bindString("list-roles-url", sxpf.MakeString(wui.listRolesURL))
+	rb.bindString("list-tags-url", sxpf.MakeString(wui.listTagsURL))
+	rb.bindString("can-refresh", sxpf.MakeBoolean(wui.canRefresh(user)))
+	rb.bindString("refresh-url", sxpf.MakeString(wui.refreshURL))
+	rb.bindString("new-zettel-links", wui.fetchNewTemplatesSxn(ctx, user))
+	rb.bindString("search-url", sxpf.MakeString(wui.searchURL))
+	rb.bindString("query-key-query", sxpf.MakeString(api.QueryKeyQuery))
+	rb.bindString("query-key-seed", sxpf.MakeString(api.QueryKeySeed))
+	rb.bindString("FOOTER", wui.calculateFooterSxn(ctx)) // TODO: use real footer
+	rb.bindString("debug-mode", sxpf.MakeBoolean(wui.debug))
+	rb.bindSymbol(wui.symMetaHeader, sxpf.Nil())
+	rb.bindSymbol(wui.symDetail, sxpf.Nil())
+	return env, rb.err
+}
+
+func (wui *WebUI) getUserRenderData(user *meta.Meta) (bool, string, string) {
+	if user == nil {
+		return false, "", ""
+	}
+	return true, wui.NewURLBuilder('h').SetZid(api.ZettelID(user.Zid.String())).String(), user.GetDefault(api.KeyUserID, "")
+}
+
+type renderBinder struct {
+	err  error
+	make func(string) (*sxpf.Symbol, error)
+	bind func(*sxpf.Symbol, sxpf.Object) error
+}
+
+func makeRenderBinder(sf sxpf.SymbolFactory, env sxpf.Environment, err error) renderBinder {
+	return renderBinder{make: sf.Make, bind: env.Bind, err: err}
+}
+func (rb *renderBinder) bindString(key string, obj sxpf.Object) {
+	if rb.err == nil {
+		sym, err := rb.make(key)
+		if err == nil {
+			rb.err = rb.bind(sym, obj)
+			return
+		}
+		rb.err = err
+	}
+}
+func (rb *renderBinder) bindSymbol(sym *sxpf.Symbol, obj sxpf.Object) {
+	if rb.err == nil {
+		rb.err = rb.bind(sym, obj)
+	}
+}
+
+func (wui *WebUI) fetchNewTemplatesSxn(ctx context.Context, user *meta.Meta) (lst *sxpf.List) {
+	if !wui.canCreate(ctx, user) {
+		return nil
+	}
+	ctx = box.NoEnrichContext(ctx)
+	menu, err := wui.box.GetZettel(ctx, id.TOCNewTemplateZid)
+	if err != nil {
+		return nil
+	}
+	refs := collect.Order(parser.ParseZettel(ctx, menu, "", wui.rtConfig))
+	for i := len(refs) - 1; i >= 0; i-- {
+		zid, err2 := id.Parse(refs[i].URL.Path)
+		if err2 != nil {
+			continue
+		}
+		m, err2 := wui.box.GetMeta(ctx, zid)
+		if err2 != nil {
+			continue
+		}
+		if !wui.policy.CanRead(user, m) {
+			continue
+		}
+		text := sxpf.MakeString(parser.NormalizedSpacedText(m.GetTitle()))
+		link := sxpf.MakeString(wui.NewURLBuilder('c').SetZid(api.ZettelID(m.Zid.String())).
+			AppendKVQuery(queryKeyAction, valueActionNew).String())
+
+		lst = lst.Cons(sxpf.Cons(text, link))
+	}
+	return lst
+}
+func (wui *WebUI) calculateFooterSxn(ctx context.Context) *sxpf.List {
+	if footerZid, err := id.Parse(wui.rtConfig.Get(ctx, nil, config.KeyFooterZettel)); err == nil {
+		if zn, err2 := wui.evalZettel.Run(ctx, footerZid, ""); err2 == nil {
+			htmlEnc := wui.getSimpleHTMLEncoder().SetUnique("footer-")
+			if content, endnotes, err3 := htmlEnc.BlocksSxn(&zn.Ast); err3 == nil {
+				if content != nil && endnotes != nil {
+					content.LastPair().SetCdr(sxpf.Cons(endnotes, nil))
+				}
+				return content
+			}
+		}
+	}
+	return nil
+}
+
+func (wui *WebUI) getSxnTemplate(ctx context.Context, zid id.Zid, env sxpf.Environment) (eval.Expr, error) {
+	wui.mxCache.RLock()
+	t, ok := wui.templateSxnCache[zid]
+	wui.mxCache.RUnlock()
+	if ok {
+		return t, nil
+	}
+
+	templateZettel, err := wui.box.GetZettel(ctx, zid)
+	if err != nil {
+		return nil, err
+	}
+
+	reader := reader.MakeReader(bytes.NewReader(templateZettel.Content.AsBytes()), reader.WithSymbolFactory(wui.sf))
+	quote.InstallQuoteReader(reader, wui.symQuote, '\'')
+	quote.InstallQuasiQuoteReader(reader, wui.symQQ, '`', wui.symUQ, ',', wui.symUQS, '@')
+
+	objs, err := reader.ReadAll()
+	if err != nil {
+		wui.log.IfErr(err).Zid(zid).Msg("reading sxn template")
+		return nil, err
+	}
+	if len(objs) != 1 {
+		return nil, fmt.Errorf("expected 1 expression in template, but got %d", len(objs))
+	}
+	form := sxpf.MakeList(wui.symQQ, objs[0])
+	t, err = wui.engine.Parse(env, form)
+	if err != nil {
+		return nil, err
+	}
+
+	wui.mxCache.Lock()
+	wui.templateSxnCache[zid] = t
+	wui.mxCache.Unlock()
+	return t, nil
+}
+
+func (wui *WebUI) evalSxnTemplate(ctx context.Context, zid id.Zid, env sxpf.Environment) (sxpf.Object, error) {
+	templateExpr, err := wui.getSxnTemplate(ctx, zid, env)
+	if err != nil {
+		return nil, err
+	}
+	return wui.engine.Execute(env, templateExpr)
+}
+
+func (wui *WebUI) renderSxnTemplate(ctx context.Context, w http.ResponseWriter, templateID id.Zid, env sxpf.Environment) error {
+	return wui.renderSxnTemplateStatus(ctx, w, http.StatusOK, templateID, env)
+}
+func (wui *WebUI) renderSxnTemplateStatus(ctx context.Context, w http.ResponseWriter, code int, templateID id.Zid, env sxpf.Environment) error {
+	detailObj, err := wui.evalSxnTemplate(ctx, templateID, env)
+	if err != nil {
+		return err
+	}
+	env.Bind(wui.symDetail, detailObj)
+
+	pageObj, err := wui.evalSxnTemplate(ctx, id.BaseTemplateZid, env)
+	if err != nil {
+		return err
+	}
+
+	gen := sxhtml.NewGenerator(wui.sf, sxhtml.WithNewline)
+	var sb bytes.Buffer
+	_, err = gen.WriteHTML(&sb, pageObj)
+	if err != nil {
+		return err
+	}
+	wui.prepareAndWriteHeader(w, code)
+	_, err = w.Write(sb.Bytes())
+	wui.log.IfErr(err).Msg("Unable to write HTML via template")
+	return nil // No error reporting, since we do not know what happended during write to client.
+}
+
+func (wui *WebUI) reportError(ctx context.Context, w http.ResponseWriter, err error) {
+	code, text := adapter.CodeMessageFromError(err)
+	if code == http.StatusInternalServerError {
+		wui.log.Error().Msg(err.Error())
+	}
+	user := server.GetUser(ctx)
+	env, err := wui.createRenderEnv(ctx, "error", api.ValueLangEN, "Error", user)
+	rb := makeRenderBinder(wui.sf, env, err)
+	rb.bindString("heading", sxpf.MakeString(http.StatusText(code)))
+	rb.bindString("message", sxpf.MakeString(text))
+	if rb.err == nil {
+		err = wui.renderSxnTemplate(ctx, w, id.ErrorTemplateZid, env)
+	}
+	if err != nil {
+		wui.log.Error().Err(err).Msg("while rendering error message")
+		fmt.Fprintf(w, "Error while rendering error message: %v", err)
+	}
+}
+
+func makeStringList(sl []string) *sxpf.List {
+	if len(sl) == 0 {
+		return nil
+	}
+	result := sxpf.Nil()
+	for i := len(sl) - 1; i >= 0; i-- {
+		result = result.Cons(sxpf.MakeString(sl[i]))
+	}
+	return result
+}

Index: web/adapter/webui/webui.go
==================================================================
--- web/adapter/webui/webui.go
+++ web/adapter/webui/webui.go
@@ -18,26 +18,26 @@
 	"sync"
 	"time"
 
 	"codeberg.org/t73fde/sxhtml"
 	"codeberg.org/t73fde/sxpf"
+	"codeberg.org/t73fde/sxpf/eval"
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/auth"
 	"zettelstore.de/z/box"
 	"zettelstore.de/z/collect"
 	"zettelstore.de/z/config"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
-	"zettelstore.de/z/encoder"
 	"zettelstore.de/z/kernel"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/parser"
 	"zettelstore.de/z/template"
 	"zettelstore.de/z/usecase"
 	"zettelstore.de/z/web/adapter"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // WebUI holds all data for delivering the web ui.
 type WebUI struct {
 	log      *logger.Logger
@@ -49,12 +49,13 @@
 	box      webuiBox
 	policy   auth.Policy
 
 	evalZettel *usecase.Evaluate
 
-	mxCache       sync.RWMutex
-	templateCache map[id.Zid]*template.Template
+	mxCache          sync.RWMutex
+	templateMusCache map[id.Zid]*template.Template
+	templateSxnCache map[id.Zid]eval.Expr
 
 	mxRoleCSSMap sync.RWMutex
 	roleCSSMap   map[string]id.Zid
 
 	tokenLifetime time.Duration
@@ -71,26 +72,43 @@
 	searchURL     string
 	createNewURL  string
 
 	sf      sxpf.SymbolFactory
 	htmlGen *sxhtml.Generator
+
+	engine        *eval.Engine
+	genHTML       *sxhtml.Generator
+	symQuote      *sxpf.Symbol
+	symQQ         *sxpf.Symbol
+	symUQ         *sxpf.Symbol
+	symUQS        *sxpf.Symbol
+	symMetaHeader *sxpf.Symbol
+	symDetail     *sxpf.Symbol
+	symA          *sxpf.Symbol
+	symAttr       *sxpf.Symbol
+	symHref       *sxpf.Symbol
+	symLi         *sxpf.Symbol
+	symDl         *sxpf.Symbol
+	symDt         *sxpf.Symbol
+	symDd         *sxpf.Symbol
 }
 
 type webuiBox interface {
 	CanCreateZettel(ctx context.Context) bool
-	GetZettel(ctx context.Context, zid id.Zid) (domain.Zettel, error)
+	GetZettel(ctx context.Context, zid id.Zid) (zettel.Zettel, error)
 	GetMeta(ctx context.Context, zid id.Zid) (*meta.Meta, error)
-	CanUpdateZettel(ctx context.Context, zettel domain.Zettel) bool
+	CanUpdateZettel(ctx context.Context, zettel zettel.Zettel) bool
 	AllowRenameZettel(ctx context.Context, zid id.Zid) bool
 	CanDeleteZettel(ctx context.Context, zid id.Zid) bool
 }
 
 // New creates a new WebUI struct.
 func New(log *logger.Logger, ab server.AuthBuilder, authz auth.AuthzManager, rtConfig config.Config, token auth.TokenManager,
 	mgr box.Manager, pol auth.Policy, evalZettel *usecase.Evaluate) *WebUI {
 	loginoutBase := ab.NewURLBuilder('i')
 	sf := sxpf.MakeMappedFactory()
+
 	wui := &WebUI{
 		log:      log,
 		debug:    kernel.Main.GetConfig(kernel.CoreService, kernel.CoreDebug).(bool),
 		ab:       ab,
 		rtConfig: rtConfig,
@@ -115,22 +133,40 @@
 		searchURL:     ab.NewURLBuilder('h').String(),
 		createNewURL:  ab.NewURLBuilder('c').String(),
 
 		sf:      sf,
 		htmlGen: sxhtml.NewGenerator(sf),
+
+		genHTML:       sxhtml.NewGenerator(sf, sxhtml.WithNewline),
+		symQuote:      sf.MustMake("quote"),
+		symQQ:         sf.MustMake("quasiquote"),
+		symUQ:         sf.MustMake("unquote"),
+		symUQS:        sf.MustMake("unquote-splicing"),
+		symDetail:     sf.MustMake("DETAIL"),
+		symMetaHeader: sf.MustMake("META-HEADER"),
+		symA:          sf.MustMake("a"),
+		symAttr:       sf.MustMake(sxhtml.NameSymAttr),
+		symHref:       sf.MustMake("href"),
+		symLi:         sf.MustMake("li"),
+		symDl:         sf.MustMake("dl"),
+		symDt:         sf.MustMake("dt"),
+		symDd:         sf.MustMake("dd"),
 	}
+	wui.engine = wui.createRenderEngine()
 	wui.observe(box.UpdateInfo{Box: mgr, Reason: box.OnReload, Zid: id.Invalid})
 	mgr.RegisterObserver(wui.observe)
 	return wui
 }
 
 func (wui *WebUI) observe(ci box.UpdateInfo) {
 	wui.mxCache.Lock()
-	if ci.Reason == box.OnReload || ci.Zid == id.BaseTemplateZid {
-		wui.templateCache = make(map[id.Zid]*template.Template, len(wui.templateCache))
+	if ci.Reason == box.OnReload || ci.Zid == id.BaseTemplateZid || ci.Zid == id.BaseTemplateZid+30000 {
+		wui.templateMusCache = make(map[id.Zid]*template.Template, len(wui.templateMusCache))
+		wui.templateSxnCache = make(map[id.Zid]eval.Expr, len(wui.templateSxnCache))
 	} else {
-		delete(wui.templateCache, ci.Zid)
+		delete(wui.templateMusCache, ci.Zid)
+		delete(wui.templateSxnCache, ci.Zid)
 	}
 	wui.mxCache.Unlock()
 	wui.mxRoleCSSMap.Lock()
 	if ci.Reason == box.OnReload || ci.Zid == id.RoleCSSMapZid {
 		wui.roleCSSMap = nil
@@ -138,22 +174,22 @@
 	wui.mxRoleCSSMap.Unlock()
 }
 
 func (wui *WebUI) cacheSetTemplate(zid id.Zid, t *template.Template) {
 	wui.mxCache.Lock()
-	wui.templateCache[zid] = t
+	wui.templateMusCache[zid] = t
 	wui.mxCache.Unlock()
 }
 
 func (wui *WebUI) cacheGetTemplate(zid id.Zid) (*template.Template, bool) {
 	wui.mxCache.RLock()
-	t, ok := wui.templateCache[zid]
+	t, ok := wui.templateMusCache[zid]
 	wui.mxCache.RUnlock()
 	return t, ok
 }
 
-func (wui *WebUI) retrieveCSSZidFromRole(ctx context.Context, m meta.Meta) (id.Zid, error) {
+func (wui *WebUI) retrieveCSSZidFromRole(ctx context.Context, m *meta.Meta) (id.Zid, error) {
 	wui.mxRoleCSSMap.RLock()
 	if wui.roleCSSMap == nil {
 		wui.mxRoleCSSMap.RUnlock()
 		wui.mxRoleCSSMap.Lock()
 		mMap, err := wui.box.GetMeta(ctx, id.RoleCSSMapZid)
@@ -201,13 +237,13 @@
 	m := meta.New(id.Invalid)
 	return wui.policy.CanCreate(user, m) && wui.box.CanCreateZettel(ctx)
 }
 
 func (wui *WebUI) canWrite(
-	ctx context.Context, user, meta *meta.Meta, content domain.Content) bool {
+	ctx context.Context, user, meta *meta.Meta, content zettel.Content) bool {
 	return wui.policy.CanWrite(user, meta, meta) &&
-		wui.box.CanUpdateZettel(ctx, domain.Zettel{Meta: meta, Content: content})
+		wui.box.CanUpdateZettel(ctx, zettel.Zettel{Meta: meta, Content: content})
 }
 
 func (wui *WebUI) canRename(ctx context.Context, user, m *meta.Meta) bool {
 	return wui.policy.CanRename(user, m) && wui.box.AllowRenameZettel(ctx, m.Zid)
 }
@@ -218,12 +254,11 @@
 
 func (wui *WebUI) canRefresh(user *meta.Meta) bool {
 	return wui.policy.CanRefresh(user)
 }
 
-func (wui *WebUI) getTemplate(
-	ctx context.Context, templateID id.Zid) (*template.Template, error) {
+func (wui *WebUI) getTemplate(ctx context.Context, templateID id.Zid) (*template.Template, error) {
 	if t, ok := wui.cacheGetTemplate(templateID); ok {
 		return t, nil
 	}
 	realTemplateZettel, err := wui.box.GetZettel(ctx, templateID)
 	if err != nil {
@@ -260,11 +295,10 @@
 	CSSBaseURL     string
 	CSSUserURL     string
 	CSSRoleURL     string
 	Title          string
 	HomeURL        string
-	WithUser       bool
 	WithAuth       bool
 	UserIsValid    bool
 	UserZettelURL  string
 	UserIdent      string
 	LoginURL       string
@@ -276,11 +310,10 @@
 	RefreshURL     string
 	NewZettelLinks simpleLinks
 	SearchURL      string
 	QueryKeyQuery  string
 	QueryKeySeed   string
-	CreateNewURL   string
 	Content        string
 	FooterHTML     string
 	DebugMode      bool
 }
 
@@ -299,11 +332,10 @@
 	data.CSSUserURL = wui.cssUserURL
 	data.CSSRoleURL = roleCSSURL
 	data.Title = title
 	data.HomeURL = wui.homeURL
 	data.WithAuth = wui.withAuth
-	data.WithUser = data.WithAuth
 	data.UserIsValid = userIsValid
 	data.UserZettelURL = userZettelURL
 	data.UserIdent = userIdent
 	data.LoginURL = wui.loginURL
 	data.LogoutURL = wui.logoutURL
@@ -314,11 +346,10 @@
 	data.RefreshURL = wui.refreshURL
 	data.NewZettelLinks = createSimpleLinks(wui.fetchNewTemplates(ctx, user))
 	data.SearchURL = wui.searchURL
 	data.QueryKeyQuery = api.QueryKeyQuery
 	data.QueryKeySeed = api.QueryKeySeed
-	data.CreateNewURL = wui.createNewURL
 	data.FooterHTML = wui.calculateFooterHTML(ctx)
 	data.DebugMode = wui.debug
 }
 
 func (wui *WebUI) getSimpleHTMLEncoder() *htmlGenerator { return wui.createGenerator(wui) }
@@ -364,14 +395,13 @@
 }
 
 func (wui *WebUI) calculateFooterHTML(ctx context.Context) string {
 	if footerZid, err := id.Parse(wui.rtConfig.Get(ctx, nil, config.KeyFooterZettel)); err == nil {
 		if zn, err2 := wui.evalZettel.Run(ctx, footerZid, ""); err2 == nil {
-			htmlEnc := encoder.Create(api.EncoderHTML)
-			var sb strings.Builder
-			if _, err2 = htmlEnc.WriteBlocks(&sb, &zn.Ast); err2 == nil {
-				return sb.String()
+			htmlEnc := wui.getSimpleHTMLEncoder().SetUnique("footer-")
+			if result, err3 := htmlEnc.BlocksString(&zn.Ast); err3 == nil {
+				return result
 			}
 		}
 	}
 	return ""
 }
@@ -383,38 +413,21 @@
 	base *baseData,
 	data interface{}) {
 	wui.renderTemplateStatus(ctx, w, http.StatusOK, templateID, base, data)
 }
 
-func (wui *WebUI) reportError(ctx context.Context, w http.ResponseWriter, err error) {
-	code, text := adapter.CodeMessageFromError(err)
-	if code == http.StatusInternalServerError {
-		wui.log.Error().Msg(err.Error())
-	}
-	user := server.GetUser(ctx)
-	var base baseData
-	wui.makeBaseData(ctx, api.ValueLangEN, "Error", "", user, &base)
-	wui.renderTemplateStatus(ctx, w, code, id.ErrorTemplateZid, &base, struct {
-		ErrorTitle string
-		ErrorText  string
-	}{
-		ErrorTitle: http.StatusText(code),
-		ErrorText:  text,
-	})
-}
-
 func (wui *WebUI) renderTemplateStatus(
 	ctx context.Context,
 	w http.ResponseWriter,
 	code int,
 	templateID id.Zid,
 	base *baseData,
 	data interface{}) {
 
-	bt, err := wui.getTemplate(ctx, id.BaseTemplateZid)
+	bt, err := wui.getTemplate(ctx, id.BaseTemplateZid+30000)
 	if err != nil {
-		wui.log.IfErr(err).Zid(id.BaseTemplateZid).Msg("Unable to get template")
+		wui.log.IfErr(err).Zid(id.BaseTemplateZid + 30000).Msg("Unable to get template")
 		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
 		return
 	}
 	t, err := wui.getTemplate(ctx, templateID)
 	if err != nil {
@@ -421,11 +434,11 @@
 		wui.log.IfErr(err).Zid(templateID).Msg("Unable to get template")
 		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
 		return
 	}
 	if user := server.GetUser(ctx); user != nil {
-		if tok, err1 := wui.token.GetToken(user, wui.tokenLifetime, auth.KindHTML); err1 == nil {
+		if tok, err1 := wui.token.GetToken(user, wui.tokenLifetime, auth.KindwebUI); err1 == nil {
 			wui.setToken(w, tok)
 		}
 	}
 	var content strings.Builder
 	err = t.Render(&content, data)

Index: web/content/content.go
==================================================================
--- web/content/content.go
+++ web/content/content.go
@@ -15,12 +15,12 @@
 import (
 	"mime"
 	"net/http"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel"
+	"zettelstore.de/z/zettel/meta"
 )
 
 const (
 	UnknownMIME  = "application/octet-stream"
 	mimeGIF      = "image/gif"
@@ -34,11 +34,11 @@
 )
 
 var encoding2mime = map[api.EncodingEnum]string{
 	api.EncoderHTML:  mimeHTML,
 	api.EncoderMD:    mimeMarkdown,
-	api.EncoderSexpr: PlainText,
+	api.EncoderSz:    PlainText,
 	api.EncoderSHTML: PlainText,
 	api.EncoderText:  PlainText,
 	api.EncoderZmk:   PlainText,
 }
 
@@ -62,12 +62,13 @@
 	meta.SyntaxMustache: PlainText,
 	meta.SyntaxNone:     "",
 	meta.SyntaxPlain:    PlainText,
 	meta.SyntaxPNG:      mimePNG,
 	meta.SyntaxSVG:      "image/svg+xml",
-	meta.SyntaxTxt:      PlainText,
+	meta.SyntaxSxn:      PlainText,
 	meta.SyntaxText:     PlainText,
+	meta.SyntaxTxt:      PlainText,
 	meta.SyntaxWebp:     mimeWEBP,
 	meta.SyntaxZmk:      "text/x-zmk; charset=utf-8",
 
 	// Additional syntaxes that are parsed as plain text.
 	"js":  "text/javascript; charset=utf-8",
@@ -109,11 +110,11 @@
 			return syntax
 		}
 		if ext, err := mime.ExtensionsByType(mt); err != nil && len(ext) > 0 {
 			return ext[0][1:]
 		}
-		if domain.IsBinary(data) {
+		if zettel.IsBinary(data) {
 			return "binary"
 		}
 	}
 	return "plain"
 }

Index: web/server/impl/impl.go
==================================================================
--- web/server/impl/impl.go
+++ web/server/impl/impl.go
@@ -16,13 +16,13 @@
 	"net/http"
 	"time"
 
 	"zettelstore.de/c/api"
 	"zettelstore.de/z/auth"
-	"zettelstore.de/z/domain/meta"
 	"zettelstore.de/z/logger"
 	"zettelstore.de/z/web/server"
+	"zettelstore.de/z/zettel/meta"
 )
 
 type myServer struct {
 	log              *logger.Logger
 	baseURL          string

Index: web/server/impl/router.go
==================================================================
--- web/server/impl/router.go
+++ web/server/impl/router.go
@@ -171,15 +171,15 @@
 func (rt *httpRouter) addUserContext(r *http.Request) *http.Request {
 	if rt.ur == nil {
 		// No auth needed
 		return r
 	}
-	k := auth.KindJSON
+	k := auth.KindAPI
 	t := getHeaderToken(r)
 	if len(t) == 0 {
 		rt.log.Debug().Msg("no jwt token found") // IP already logged: ServeHTTP
-		k = auth.KindHTML
+		k = auth.KindwebUI
 		t = getSessionToken(r)
 	}
 	if len(t) == 0 {
 		rt.log.Debug().Msg("no auth token found in request") // IP already logged: ServeHTTP
 		return r

Index: web/server/server.go
==================================================================
--- web/server/server.go
+++ web/server/server.go
@@ -15,12 +15,12 @@
 	"context"
 	"net/http"
 	"time"
 
 	"zettelstore.de/c/api"
-	"zettelstore.de/z/domain/id"
-	"zettelstore.de/z/domain/meta"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
 )
 
 // UserRetriever allows to retrieve user data based on a given zettel identifier.
 type UserRetriever interface {
 	GetUser(ctx context.Context, zid id.Zid, ident string) (*meta.Meta, error)

Index: www/build.md
==================================================================
--- www/build.md
+++ www/build.md
@@ -45,10 +45,12 @@
   into a freshly created directory <tt>bin</tt>.
 * `check`: checks the current state of the working directory to be ready for
   release (or commit).
 * `clean`: removes the build directories and cleans the Go cache.
 * `version`: prints the current version information.
+* `tools`: installs / updates the tools described above: staticcheck, shadow,
+  unparam, govulncheck.
 
 Therefore, the easiest way to build your own version of the Zettelstore
 software is to execute the command
 
 ```

Index: www/changes.wiki
==================================================================
--- www/changes.wiki
+++ www/changes.wiki
@@ -1,11 +1,62 @@
 <title>Change Log</title>
 
 <a id="0_12"></a>
 <h2>Changes for Version 0.12.0 (pending)</h2>
+  *  Query expression is allowed to search for the "context" of a zettel.
+     Previously, this was a separate call, without adding a search expression
+     / action expression.
+     (breaking)
+  *  "sexpr" encoding is renamed to "sz" encoding. This will affect mostly the
+     API. Additionally, all string "sexpr" are renamed to "sz" also. "Sz" is
+     the short form for "symbolic expression for zettel", similar to "shtml"
+     that is the short form for "symbolic expression for HTML".
+     (breaking)
+  *  Render footer zettel on all WebUI pages.
+     (fix: webui)
+  *  Query search operator "=" now compares for equality, ":" compares
+     depending on the value type.
+     (minor: api, webui)
+  *  Search term <tt>PICK</tt> now respects the original sort order. This makes
+     it more useful and orthogonal to <tt>RANDOM</tt> and <tt>LIMIT</tt>. As
+     a side effect, zettel lists retrieved via the API are no longer sorted. In
+     case you want a specific order, you must specify it explicit.
+     (minor: api, webui)
+  *  New metadata key <tt>expire</tt> records a timestamp when a zettel should
+     be treated as, well, expired.
+     (minor)
+  *  New metadata kays <tt>superior</tt> and <tt>subordinate</tt> (calculated
+     from <tt>superior</tt>) allow to specify a hierarchy between zettel, if
+     needed.
+     (minor)
+  *  Metadata keys with suffix <tt>-date</tt> and <tt>-time</tt> are treated as
+     timestamp values.
+     (minor)
+  *  <tt>sexpr</tt> zettel encoding is now documented in the manual.
+     (minor: manual)
+  *  Build tool allows to install / update external Go tools needed to build
+     the software.
+     (minor)
+  *  Show only useful metadata on WebUI, not the internal metadata.
+     (minor: webui)
+  *  The use of the <tt>json</tt> zettel encoding is deprecated. Support for
+     this encoding may be removed in future versions. Please use the new
+     <tt>data</tt> encoding instead.
+     (deprecated: api)
 
 <a id="0_11"></a>
+<h2>Changes for Version 0.11.2 (2023-04-16)</h2>
+  *  Render footer zettel on all WebUI pages.
+     Backported from 0.12.0.
+     Many thanks to HK for reporting it!
+     (fix: webui)
+
+<h2>Changes for Version 0.11.1 (2023-03-28)</h2>
+  *  Make <tt>PICK</tt> search term a little bit more deterministic so that the
+     &ldquo;Save As Zettel&rdquo; button produces the same list.
+     (fix: webui)
+
 <h2>Changes for Version 0.11.0 (2023-03-27)</h2>
   *  Remove ZJSON encoding. It was announced in version 0.10.0. Use Sexpr
      encoding instead.
      (breaking)
   *  Title of a zettel is no longer interpreted as Zettelmarkup text. Now it is

Index: www/download.wiki
==================================================================
--- www/download.wiki
+++ www/download.wiki
@@ -7,20 +7,20 @@
   *  However, it is in use by the main developer since March 2020 without any damage.
   *  It may be useful for you. It is useful for me.
   *  Take a look at the [https://zettelstore.de/manual/|manual] to know how to start and use it.
 
 <h2>ZIP-ped Executables</h2>
-Build: <code>v0.11.0</code> (2023-03-27).
+Build: <code>v0.11.2</code> (2023-04-16).
 
-  *  [/uv/zettelstore-0.11.0-linux-amd64.zip|Linux] (amd64)
-  *  [/uv/zettelstore-0.11.0-linux-arm.zip|Linux] (arm6, e.g. Raspberry Pi)
-  *  [/uv/zettelstore-0.11.0-darwin-amd64.zip|macOS] (amd64)
-  *  [/uv/zettelstore-0.11.0-darwin-arm64.zip|macOS] (arm64, aka Apple silicon)
-  *  [/uv/zettelstore-0.11.0-windows-amd64.zip|Windows] (amd64)
+  *  [/uv/zettelstore-0.11.2-linux-amd64.zip|Linux] (amd64)
+  *  [/uv/zettelstore-0.11.2-linux-arm.zip|Linux] (arm6, e.g. Raspberry Pi)
+  *  [/uv/zettelstore-0.11.2-darwin-amd64.zip|macOS] (amd64)
+  *  [/uv/zettelstore-0.11.2-darwin-arm64.zip|macOS] (arm64, aka Apple silicon)
+  *  [/uv/zettelstore-0.11.2-windows-amd64.zip|Windows] (amd64)
 
 Unzip the appropriate file, install and execute Zettelstore according to the manual.
 
 <h2>Zettel for the manual</h2>
 As a starter, you can download the zettel for the manual
-[/uv/manual-0.11.0.zip|here].
+[/uv/manual-0.11.2.zip|here].
 Just unzip the contained files and put them into your zettel folder or
 configure a file box to read the zettel directly from the ZIP file.

Index: www/index.wiki
==================================================================
--- www/index.wiki
+++ www/index.wiki
@@ -20,26 +20,25 @@
 access Zettelstore via its API more easily,
 [https://zettelstore.de/contrib|Zettelstore Contrib] contains contributed
 software, which often connects to Zettelstore via its API. Some of the software
 packages may be experimental.
 
-[https://twitter.com/zettelstore|Stay]
-<a rel="me" href="https://nerdculture.de/@zettelstore">tuned</a>&nbsp;&hellip;
+[https://twitter.com/search?q=%40t73fde%20zettelstore&f=live|Stay tuned]&nbsp;&hellip;
 <hr>
-<h3>Latest Release: 0.11.0 (2023-03-27)</h3>
+<h3>Latest Release: 0.11.2 (2023-04-16)</h3>
   *  [./download.wiki|Download]
   *  [./changes.wiki#0_11|Change summary]
-  *  [/timeline?p=v0.11.0&bt=v0.10.0&y=ci|Check-ins for version 0.11.0],
-     [/vdiff?to=v0.11.0&from=v0.10.0|content diff]
+  *  [/timeline?p=v0.11.2&bt=v0.10.0&y=ci|Check-ins for version 0.11.2],
+     [/vdiff?to=v0.11.2&from=v0.10.0|content diff]
   *  [/timeline?df=v0.11.0&y=ci|Check-ins derived from the 0.11.0 release],
      [/vdiff?from=v0.11.0&to=trunk|content diff]
   *  [./plan.wiki|Limitations and planned improvements]
   *  [/timeline?t=release|Timeline of all past releases]
 
 <hr>
 <h2>Build instructions</h2>
-Just install [https://golang.org/dl/|Go] and some Go-based tools. Please read
+Just install [https://go.dev/dl/|Go] and some Go-based tools. Please read
 the [./build.md|instructions] for details.
 
   *  [/dir?ci=trunk|Source code]
   *  [/download|Download the source code] as a tarball or a ZIP file
      (you must [/login|login] as user &quot;anonymous&quot;).

ADDED   zettel/content.go
Index: zettel/content.go
==================================================================
--- zettel/content.go
+++ zettel/content.go
@@ -0,0 +1,123 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package zettel
+
+import (
+	"bytes"
+	"encoding/base64"
+	"errors"
+	"io"
+	"unicode"
+	"unicode/utf8"
+
+	"zettelstore.de/z/input"
+)
+
+// Content is just the content of a zettel.
+type Content struct {
+	data     []byte
+	isBinary bool
+}
+
+// NewContent creates a new content from a string.
+func NewContent(data []byte) Content {
+	return Content{data: data, isBinary: IsBinary(data)}
+}
+
+// Length returns the number of bytes stored.
+func (zc *Content) Length() int { return len(zc.data) }
+
+// Equal compares two content values.
+func (zc *Content) Equal(o *Content) bool {
+	if zc == nil {
+		return o == nil
+	}
+	if zc.isBinary != o.isBinary {
+		return false
+	}
+	return bytes.Equal(zc.data, o.data)
+}
+
+// Write it to a Writer
+func (zc *Content) Write(w io.Writer) (int, error) {
+	return w.Write(zc.data)
+}
+
+// AsString returns the content itself is a string.
+func (zc *Content) AsString() string { return string(zc.data) }
+
+// AsBytes returns the content itself is a byte slice.
+func (zc *Content) AsBytes() []byte { return zc.data }
+
+// IsBinary returns true if the content contains non-unicode values or is,
+// interpreted a text, with a high probability binary content.
+func (zc *Content) IsBinary() bool { return zc.isBinary }
+
+// TrimSpace remove some space character in content, if it is not binary content.
+func (zc *Content) TrimSpace() {
+	if zc.isBinary {
+		return
+	}
+	inp := input.NewInput(zc.data)
+	pos := inp.Pos
+	for inp.Ch != input.EOS {
+		if input.IsEOLEOS(inp.Ch) {
+			inp.Next()
+			pos = inp.Pos
+			continue
+		}
+		if !input.IsSpace(inp.Ch) {
+			break
+		}
+		inp.Next()
+	}
+	zc.data = bytes.TrimRightFunc(inp.Src[pos:], unicode.IsSpace)
+}
+
+// Encode content for future transmission.
+func (zc *Content) Encode() (data, encoding string) {
+	if !zc.isBinary {
+		return zc.AsString(), ""
+	}
+	return base64.StdEncoding.EncodeToString(zc.data), "base64"
+}
+
+// SetDecoded content to the decoded value of the given string.
+func (zc *Content) SetDecoded(data, encoding string) error {
+	switch encoding {
+	case "":
+		zc.data = []byte(data)
+	case "base64":
+		decoded, err := base64.StdEncoding.DecodeString(data)
+		if err != nil {
+			return err
+		}
+		zc.data = decoded
+	default:
+		return errors.New("unknown encoding " + encoding)
+	}
+	zc.isBinary = IsBinary(zc.data)
+	return nil
+}
+
+// IsBinary returns true if the given data appears to be non-text data.
+func IsBinary(data []byte) bool {
+	if !utf8.Valid(data) {
+		return true
+	}
+	l := len(data)
+	for i := 0; i < l; i++ {
+		if data[i] == 0 {
+			return true
+		}
+	}
+	return false
+}

ADDED   zettel/content_test.go
Index: zettel/content_test.go
==================================================================
--- zettel/content_test.go
+++ zettel/content_test.go
@@ -0,0 +1,66 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package zettel_test
+
+import (
+	"testing"
+
+	"zettelstore.de/z/zettel"
+)
+
+func TestContentIsBinary(t *testing.T) {
+	t.Parallel()
+	td := []struct {
+		s   string
+		exp bool
+	}{
+		{"abc", false},
+		{"äöü", false},
+		{"", false},
+		{string([]byte{0}), true},
+	}
+	for i, tc := range td {
+		content := zettel.NewContent([]byte(tc.s))
+		got := content.IsBinary()
+		if got != tc.exp {
+			t.Errorf("TC=%d: expected %v, got %v", i, tc.exp, got)
+		}
+	}
+}
+
+func TestTrimSpace(t *testing.T) {
+	t.Parallel()
+	testcases := []struct {
+		in, exp string
+	}{
+		{"", ""},
+		{" ", ""},
+		{"abc", "abc"},
+		{" abc", " abc"},
+		{"abc ", "abc"},
+		{"abc \n", "abc"},
+		{"abc\n ", "abc"},
+		{"\nabc", "abc"},
+		{" \nabc", "abc"},
+		{" \n abc", " abc"},
+		{" \n\n abc", " abc"},
+		{" \n \n abc", " abc"},
+		{" \n \n abc \n \n ", " abc"},
+	}
+	for _, tc := range testcases {
+		c := zettel.NewContent([]byte(tc.in))
+		c.TrimSpace()
+		got := c.AsString()
+		if got != tc.exp {
+			t.Errorf("TrimSpace(%q) should be %q, but got %q", tc.in, tc.exp, got)
+		}
+	}
+}

ADDED   zettel/id/id.go
Index: zettel/id/id.go
==================================================================
--- zettel/id/id.go
+++ zettel/id/id.go
@@ -0,0 +1,162 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+// Package id provides zettel specific types, constants, and functions about
+// zettel identifier.
+package id
+
+import (
+	"strconv"
+	"time"
+
+	"zettelstore.de/c/api"
+)
+
+// Zid is the internal identifier of a zettel. Typically, it is a
+// time stamp of the form "YYYYMMDDHHmmSS" converted to an unsigned integer.
+// A zettelstore implementation should try to set the last two digits to zero,
+// e.g. the seconds should be zero,
+type Zid uint64
+
+// Some important ZettelIDs.
+const (
+	Invalid = Zid(0) // Invalid is a Zid that will never be valid
+)
+
+// ZettelIDs that are used as Zid more than once.
+//
+// Note: if you change some values, ensure that you also change them in the
+// Constant box. They are mentioned there literally, because these
+// constants are not available there.
+var (
+	ConfigurationZid  = MustParse(api.ZidConfiguration)
+	BaseTemplateZid   = MustParse(api.ZidBaseTemplate)
+	LoginTemplateZid  = MustParse(api.ZidLoginTemplate)
+	ListTemplateZid   = MustParse(api.ZidListTemplate)
+	ZettelTemplateZid = MustParse(api.ZidZettelTemplate)
+	InfoTemplateZid   = MustParse(api.ZidInfoTemplate)
+	FormTemplateZid   = MustParse(api.ZidFormTemplate)
+	RenameTemplateZid = MustParse(api.ZidRenameTemplate)
+	DeleteTemplateZid = MustParse(api.ZidDeleteTemplate)
+	ErrorTemplateZid  = MustParse(api.ZidErrorTemplate)
+	RoleCSSMapZid     = MustParse(api.ZidRoleCSSMap)
+	EmojiZid          = MustParse(api.ZidEmoji)
+	TOCNewTemplateZid = MustParse(api.ZidTOCNewTemplate)
+	DefaultHomeZid    = MustParse(api.ZidDefaultHome)
+)
+
+const maxZid = 99999999999999
+
+// ParseUint interprets a string as a possible zettel identifier
+// and returns its integer value.
+func ParseUint(s string) (uint64, error) {
+	res, err := strconv.ParseUint(s, 10, 47)
+	if err != nil {
+		return 0, err
+	}
+	if res == 0 || res > maxZid {
+		return res, strconv.ErrRange
+	}
+	return res, nil
+}
+
+// Parse interprets a string as a zettel identification and
+// returns its value.
+func Parse(s string) (Zid, error) {
+	if len(s) != 14 {
+		return Invalid, strconv.ErrSyntax
+	}
+	res, err := ParseUint(s)
+	if err != nil {
+		return Invalid, err
+	}
+	return Zid(res), nil
+}
+
+// MustParse tries to interpret a string as a zettel identifier and returns
+// its value or panics otherwise.
+func MustParse(s api.ZettelID) Zid {
+	zid, err := Parse(string(s))
+	if err == nil {
+		return zid
+	}
+	panic(err)
+}
+
+// String converts the zettel identification to a string of 14 digits.
+// Only defined for valid ids.
+func (zid Zid) String() string {
+	var result [14]byte
+	zid.toByteArray(&result)
+	return string(result[:])
+}
+
+// Bytes converts the zettel identification to a byte slice of 14 digits.
+// Only defined for valid ids.
+func (zid Zid) Bytes() []byte {
+	var result [14]byte
+	zid.toByteArray(&result)
+	return result[:]
+}
+
+// toByteArray converts the Zid into a fixed byte array, usable for printing.
+//
+// Based on idea by Daniel Lemire: "Converting integers to fix-digit representations quickly"
+// https://lemire.me/blog/2021/11/18/converting-integers-to-fix-digit-representations-quickly/
+func (zid Zid) toByteArray(result *[14]byte) {
+	date := uint64(zid) / 1000000
+	fullyear := date / 10000
+	century := fullyear / 100
+	year := fullyear % 100
+	monthday := date % 10000
+	month := monthday / 100
+	day := monthday % 100
+	time := uint64(zid) % 1000000
+	hmtime := time / 100
+	second := time % 100
+	hour := hmtime / 100
+	minute := hmtime % 100
+	result[0] = byte(century/10) + '0'
+	result[1] = byte(century%10) + '0'
+	result[2] = byte(year/10) + '0'
+	result[3] = byte(year%10) + '0'
+	result[4] = byte(month/10) + '0'
+	result[5] = byte(month%10) + '0'
+	result[6] = byte(day/10) + '0'
+	result[7] = byte(day%10) + '0'
+	result[8] = byte(hour/10) + '0'
+	result[9] = byte(hour%10) + '0'
+	result[10] = byte(minute/10) + '0'
+	result[11] = byte(minute%10) + '0'
+	result[12] = byte(second/10) + '0'
+	result[13] = byte(second%10) + '0'
+}
+
+// IsValid determines if zettel id is a valid one, e.g. consists of max. 14 digits.
+func (zid Zid) IsValid() bool { return 0 < zid && zid <= maxZid }
+
+// ZidLayout to transform a date into a Zid and into other internal dates.
+const ZidLayout = "20060102150405"
+
+// New returns a new zettel id based on the current time.
+func New(withSeconds bool) Zid {
+	now := time.Now().Local()
+	var s string
+	if withSeconds {
+		s = now.Format(ZidLayout)
+	} else {
+		s = now.Format("20060102150400")
+	}
+	res, err := Parse(s)
+	if err != nil {
+		panic(err)
+	}
+	return res
+}

ADDED   zettel/id/id_test.go
Index: zettel/id/id_test.go
==================================================================
--- zettel/id/id_test.go
+++ zettel/id/id_test.go
@@ -0,0 +1,87 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+// Package id_test provides unit tests for testing zettel id specific functions.
+package id_test
+
+import (
+	"testing"
+
+	"zettelstore.de/z/zettel/id"
+)
+
+func TestIsValid(t *testing.T) {
+	t.Parallel()
+	validIDs := []string{
+		"00000000000001",
+		"00000000000020",
+		"00000000000300",
+		"00000000004000",
+		"00000000050000",
+		"00000000600000",
+		"00000007000000",
+		"00000080000000",
+		"00000900000000",
+		"00001000000000",
+		"00020000000000",
+		"00300000000000",
+		"04000000000000",
+		"50000000000000",
+		"99999999999999",
+		"00001007030200",
+		"20200310195100",
+	}
+
+	for i, sid := range validIDs {
+		zid, err := id.Parse(sid)
+		if err != nil {
+			t.Errorf("i=%d: sid=%q is not valid, but should be. err=%v", i, sid, err)
+		}
+		s := zid.String()
+		if s != sid {
+			t.Errorf(
+				"i=%d: zid=%v does not format to %q, but to %q", i, zid, sid, s)
+		}
+	}
+
+	invalidIDs := []string{
+		"", "0", "a",
+		"00000000000000",
+		"0000000000000a",
+		"000000000000000",
+		"20200310T195100",
+	}
+
+	for i, sid := range invalidIDs {
+		if zid, err := id.Parse(sid); err == nil {
+			t.Errorf("i=%d: sid=%q is valid (zid=%s), but should not be", i, sid, zid)
+		}
+	}
+}
+
+var sResult string // to disable compiler optimization in loop below
+
+func BenchmarkString(b *testing.B) {
+	var s string
+	for n := 0; n < b.N; n++ {
+		s = id.Zid(12345678901200).String()
+	}
+	sResult = s
+}
+
+var bResult []byte // to disable compiler optimization in loop below
+
+func BenchmarkBytes(b *testing.B) {
+	var bs []byte
+	for n := 0; n < b.N; n++ {
+		bs = id.Zid(12345678901200).Bytes()
+	}
+	bResult = bs
+}

ADDED   zettel/id/set.go
Index: zettel/id/set.go
==================================================================
--- zettel/id/set.go
+++ zettel/id/set.go
@@ -0,0 +1,119 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2021-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package id
+
+// Set is a set of zettel identifier
+type Set map[Zid]struct{}
+
+// NewSet returns a new set of identifier with the given initial values.
+func NewSet(zids ...Zid) Set {
+	l := len(zids)
+	if l < 8 {
+		l = 8
+	}
+	result := make(Set, l)
+	result.AddSlice(zids)
+	return result
+}
+
+// NewSetCap returns a new set of identifier with the given capacity and initial values.
+func NewSetCap(c int, zids ...Zid) Set {
+	l := len(zids)
+	if c < l {
+		c = l
+	}
+	if c < 8 {
+		c = 8
+	}
+	result := make(Set, c)
+	result.AddSlice(zids)
+	return result
+}
+
+// Zid adds a Zid to the set.
+func (s Set) Zid(zid Zid) Set {
+	if s == nil {
+		return NewSet(zid)
+	}
+	s[zid] = struct{}{}
+	return s
+}
+
+// Contains return true if the set is nil or if the set contains the given Zettel identifier.
+func (s Set) Contains(zid Zid) bool {
+	if s != nil {
+		_, found := s[zid]
+		return found
+	}
+	return true
+}
+
+// Add all member from the other set.
+func (s Set) Add(other Set) Set {
+	if s == nil {
+		return other
+	}
+	for zid := range other {
+		s[zid] = struct{}{}
+	}
+	return s
+}
+
+// AddSlice adds all identifier of the given slice to the set.
+func (s Set) AddSlice(sl Slice) {
+	for _, zid := range sl {
+		s[zid] = struct{}{}
+	}
+}
+
+// Sorted returns the set as a sorted slice of zettel identifier.
+func (s Set) Sorted() Slice {
+	if l := len(s); l > 0 {
+		result := make(Slice, 0, l)
+		for zid := range s {
+			result = append(result, zid)
+		}
+		result.Sort()
+		return result
+	}
+	return nil
+}
+
+// IntersectOrSet removes all zettel identifier that are not in the other set.
+// Both sets can be modified by this method. One of them is the set returned.
+// It contains the intersection of both, if s is not nil.
+//
+// If s == nil, then the other set is always returned.
+func (s Set) IntersectOrSet(other Set) Set {
+	if s == nil {
+		return other
+	}
+	if len(s) > len(other) {
+		s, other = other, s
+	}
+	for zid := range s {
+		_, otherOk := other[zid]
+		if !otherOk {
+			delete(s, zid)
+		}
+	}
+	return s
+}
+
+// Remove all zettel identifier from 's' that are in the set 'other'.
+func (s Set) Remove(other Set) {
+	if s == nil || other == nil {
+		return
+	}
+	for zid := range other {
+		delete(s, zid)
+	}
+}

ADDED   zettel/id/set_test.go
Index: zettel/id/set_test.go
==================================================================
--- zettel/id/set_test.go
+++ zettel/id/set_test.go
@@ -0,0 +1,149 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2021-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package id_test
+
+import (
+	"testing"
+
+	"zettelstore.de/z/zettel/id"
+)
+
+func TestSetContains(t *testing.T) {
+	t.Parallel()
+	testcases := []struct {
+		s   id.Set
+		zid id.Zid
+		exp bool
+	}{
+		{nil, id.Invalid, true},
+		{nil, 14, true},
+		{id.NewSet(), id.Invalid, false},
+		{id.NewSet(), 1, false},
+		{id.NewSet(), id.Invalid, false},
+		{id.NewSet(1), 1, true},
+	}
+	for i, tc := range testcases {
+		got := tc.s.Contains(tc.zid)
+		if got != tc.exp {
+			t.Errorf("%d: %v.Contains(%v) == %v, but got %v", i, tc.s, tc.zid, tc.exp, got)
+		}
+	}
+}
+
+func TestSetAdd(t *testing.T) {
+	t.Parallel()
+	testcases := []struct {
+		s1, s2 id.Set
+		exp    id.Slice
+	}{
+		{nil, nil, nil},
+		{id.NewSet(), nil, nil},
+		{id.NewSet(), id.NewSet(), nil},
+		{nil, id.NewSet(1), id.Slice{1}},
+		{id.NewSet(1), nil, id.Slice{1}},
+		{id.NewSet(1), id.NewSet(), id.Slice{1}},
+		{id.NewSet(1), id.NewSet(2), id.Slice{1, 2}},
+		{id.NewSet(1), id.NewSet(1), id.Slice{1}},
+	}
+	for i, tc := range testcases {
+		sl1 := tc.s1.Sorted()
+		sl2 := tc.s2.Sorted()
+		got := tc.s1.Add(tc.s2).Sorted()
+		if !got.Equal(tc.exp) {
+			t.Errorf("%d: %v.Add(%v) should be %v, but got %v", i, sl1, sl2, tc.exp, got)
+		}
+	}
+}
+
+func TestSetSorted(t *testing.T) {
+	t.Parallel()
+	testcases := []struct {
+		set id.Set
+		exp id.Slice
+	}{
+		{nil, nil},
+		{id.NewSet(), nil},
+		{id.NewSet(9, 4, 6, 1, 7), id.Slice{1, 4, 6, 7, 9}},
+	}
+	for i, tc := range testcases {
+		got := tc.set.Sorted()
+		if !got.Equal(tc.exp) {
+			t.Errorf("%d: %v.Sorted() should be %v, but got %v", i, tc.set, tc.exp, got)
+		}
+	}
+}
+
+func TestSetIntersectOrSet(t *testing.T) {
+	t.Parallel()
+	testcases := []struct {
+		s1, s2 id.Set
+		exp    id.Slice
+	}{
+		{nil, nil, nil},
+		{id.NewSet(), nil, nil},
+		{nil, id.NewSet(), nil},
+		{id.NewSet(), id.NewSet(), nil},
+		{id.NewSet(1), nil, nil},
+		{nil, id.NewSet(1), id.Slice{1}},
+		{id.NewSet(1), id.NewSet(), nil},
+		{id.NewSet(), id.NewSet(1), nil},
+		{id.NewSet(1), id.NewSet(2), nil},
+		{id.NewSet(2), id.NewSet(1), nil},
+		{id.NewSet(1), id.NewSet(1), id.Slice{1}},
+	}
+	for i, tc := range testcases {
+		sl1 := tc.s1.Sorted()
+		sl2 := tc.s2.Sorted()
+		got := tc.s1.IntersectOrSet(tc.s2).Sorted()
+		if !got.Equal(tc.exp) {
+			t.Errorf("%d: %v.IntersectOrSet(%v) should be %v, but got %v", i, sl1, sl2, tc.exp, got)
+		}
+	}
+}
+
+func TestSetRemove(t *testing.T) {
+	t.Parallel()
+	testcases := []struct {
+		s1, s2 id.Set
+		exp    id.Slice
+	}{
+		{nil, nil, nil},
+		{id.NewSet(), nil, nil},
+		{id.NewSet(), id.NewSet(), nil},
+		{id.NewSet(1), nil, id.Slice{1}},
+		{id.NewSet(1), id.NewSet(), id.Slice{1}},
+		{id.NewSet(1), id.NewSet(2), id.Slice{1}},
+		{id.NewSet(1), id.NewSet(1), id.Slice{}},
+	}
+	for i, tc := range testcases {
+		sl1 := tc.s1.Sorted()
+		sl2 := tc.s2.Sorted()
+		newS1 := id.NewSet(sl1...)
+		newS1.Remove(tc.s2)
+		got := newS1.Sorted()
+		if !got.Equal(tc.exp) {
+			t.Errorf("%d: %v.Remove(%v) should be %v, but got %v", i, sl1, sl2, tc.exp, got)
+		}
+	}
+}
+
+//	func BenchmarkSet(b *testing.B) {
+//		s := id.Set{}
+//		for i := 0; i < b.N; i++ {
+//			s[id.Zid(i)] = true
+//		}
+//	}
+func BenchmarkSet(b *testing.B) {
+	s := id.Set{}
+	for i := 0; i < b.N; i++ {
+		s[id.Zid(i)] = struct{}{}
+	}
+}

ADDED   zettel/id/slice.go
Index: zettel/id/slice.go
==================================================================
--- zettel/id/slice.go
+++ zettel/id/slice.go
@@ -0,0 +1,67 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2021-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package id
+
+import (
+	"sort"
+	"strings"
+)
+
+// Slice is a sequence of zettel identifier. A special case is a sorted slice.
+type Slice []Zid
+
+func (zs Slice) Len() int           { return len(zs) }
+func (zs Slice) Less(i, j int) bool { return zs[i] < zs[j] }
+func (zs Slice) Swap(i, j int)      { zs[i], zs[j] = zs[j], zs[i] }
+
+// Sort a slice of Zids.
+func (zs Slice) Sort() { sort.Sort(zs) }
+
+// Copy a zettel identifier slice
+func (zs Slice) Copy() Slice {
+	if zs == nil {
+		return nil
+	}
+	result := make(Slice, len(zs))
+	copy(result, zs)
+	return result
+}
+
+// Equal reports whether zs and other are the same length and contain the samle zettel
+// identifier. A nil argument is equivalent to an empty slice.
+func (zs Slice) Equal(other Slice) bool {
+	if len(zs) != len(other) {
+		return false
+	}
+	if len(zs) == 0 {
+		return true
+	}
+	for i, e := range zs {
+		if e != other[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func (zs Slice) String() string {
+	if len(zs) == 0 {
+		return ""
+	}
+	var sb strings.Builder
+	for i, zid := range zs {
+		if i > 0 {
+			sb.WriteByte(' ')
+		}
+		sb.WriteString(zid.String())
+	}
+	return sb.String()
+}

ADDED   zettel/id/slice_test.go
Index: zettel/id/slice_test.go
==================================================================
--- zettel/id/slice_test.go
+++ zettel/id/slice_test.go
@@ -0,0 +1,86 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2021-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package id_test
+
+import (
+	"testing"
+
+	"zettelstore.de/z/zettel/id"
+)
+
+func TestSliceSort(t *testing.T) {
+	t.Parallel()
+	zs := id.Slice{9, 4, 6, 1, 7}
+	zs.Sort()
+	exp := id.Slice{1, 4, 6, 7, 9}
+	if !zs.Equal(exp) {
+		t.Errorf("Slice.Sort did not work. Expected %v, got %v", exp, zs)
+	}
+}
+
+func TestCopy(t *testing.T) {
+	t.Parallel()
+	var orig id.Slice
+	got := orig.Copy()
+	if got != nil {
+		t.Errorf("Nil copy resulted in %v", got)
+	}
+	orig = id.Slice{9, 4, 6, 1, 7}
+	got = orig.Copy()
+	if !orig.Equal(got) {
+		t.Errorf("Slice.Copy did not work. Expected %v, got %v", orig, got)
+	}
+}
+
+func TestSliceEqual(t *testing.T) {
+	t.Parallel()
+	testcases := []struct {
+		s1, s2 id.Slice
+		exp    bool
+	}{
+		{nil, nil, true},
+		{nil, id.Slice{}, true},
+		{nil, id.Slice{1}, false},
+		{id.Slice{1}, id.Slice{1}, true},
+		{id.Slice{1}, id.Slice{2}, false},
+		{id.Slice{1, 2}, id.Slice{2, 1}, false},
+		{id.Slice{1, 2}, id.Slice{1, 2}, true},
+	}
+	for i, tc := range testcases {
+		got := tc.s1.Equal(tc.s2)
+		if got != tc.exp {
+			t.Errorf("%d/%v.Equal(%v)==%v, but got %v", i, tc.s1, tc.s2, tc.exp, got)
+		}
+		got = tc.s2.Equal(tc.s1)
+		if got != tc.exp {
+			t.Errorf("%d/%v.Equal(%v)==%v, but got %v", i, tc.s2, tc.s1, tc.exp, got)
+		}
+	}
+}
+
+func TestSliceString(t *testing.T) {
+	t.Parallel()
+	testcases := []struct {
+		in  id.Slice
+		exp string
+	}{
+		{nil, ""},
+		{id.Slice{}, ""},
+		{id.Slice{1}, "00000000000001"},
+		{id.Slice{1, 2}, "00000000000001 00000000000002"},
+	}
+	for i, tc := range testcases {
+		got := tc.in.String()
+		if got != tc.exp {
+			t.Errorf("%d/%v: expected %q, but got %q", i, tc.in, tc.exp, got)
+		}
+	}
+}

ADDED   zettel/meta/collection.go
Index: zettel/meta/collection.go
==================================================================
--- zettel/meta/collection.go
+++ zettel/meta/collection.go
@@ -0,0 +1,110 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2022-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package meta
+
+import "sort"
+
+// Arrangement stores metadata within its categories.
+// Typecally a category might be a tag name, a role name, a syntax value.
+type Arrangement map[string][]*Meta
+
+// CreateArrangement by inspecting a given key and use the found
+// value as a category.
+func CreateArrangement(metaList []*Meta, key string) Arrangement {
+	if len(metaList) == 0 {
+		return nil
+	}
+	descr := Type(key)
+	if descr == nil {
+		return nil
+	}
+	if descr.IsSet {
+		return createSetArrangement(metaList, key)
+	}
+	return createSimplearrangement(metaList, key)
+}
+
+func createSetArrangement(metaList []*Meta, key string) Arrangement {
+	a := make(Arrangement)
+	for _, m := range metaList {
+		if vals, ok := m.GetList(key); ok {
+			for _, val := range vals {
+				a[val] = append(a[val], m)
+			}
+		}
+	}
+	return a
+}
+
+func createSimplearrangement(metaList []*Meta, key string) Arrangement {
+	a := make(Arrangement)
+	for _, m := range metaList {
+		if val, ok := m.Get(key); ok && val != "" {
+			a[val] = append(a[val], m)
+		}
+	}
+	return a
+}
+
+// Counted returns the list of categories, together with the number of
+// metadata for each category.
+func (a Arrangement) Counted() CountedCategories {
+	if len(a) == 0 {
+		return nil
+	}
+	result := make(CountedCategories, 0, len(a))
+	for cat, metas := range a {
+		result = append(result, CountedCategory{Name: cat, Count: len(metas)})
+	}
+	return result
+}
+
+// CountedCategory contains of a name and the number how much this name occured
+// somewhere.
+type CountedCategory struct {
+	Name  string
+	Count int
+}
+
+// CountedCategories is the list of CountedCategories.
+// Every name must occur only once.
+type CountedCategories []CountedCategory
+
+// SortByName sorts the list by the name attribute.
+// Since each name must occur only once, two CountedCategories cannot have
+// the same name.
+func (ccs CountedCategories) SortByName() {
+	sort.Slice(ccs, func(i, j int) bool { return ccs[i].Name < ccs[j].Name })
+}
+
+// SortByCount sorts the list by the count attribute, descending.
+// If two counts are equal, elements are sorted by name.
+func (ccs CountedCategories) SortByCount() {
+	sort.Slice(ccs, func(i, j int) bool {
+		iCount, jCount := ccs[i].Count, ccs[j].Count
+		if iCount > jCount {
+			return true
+		}
+		if iCount == jCount {
+			return ccs[i].Name < ccs[j].Name
+		}
+		return false
+	})
+}
+
+// Categories returns just the category names.
+func (ccs CountedCategories) Categories() []string {
+	result := make([]string, len(ccs))
+	for i, cc := range ccs {
+		result[i] = cc.Name
+	}
+	return result
+}

ADDED   zettel/meta/meta.go
Index: zettel/meta/meta.go
==================================================================
--- zettel/meta/meta.go
+++ zettel/meta/meta.go
@@ -0,0 +1,417 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+// Package meta provides the zettel specific type 'meta'.
+package meta
+
+import (
+	"regexp"
+	"sort"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	"zettelstore.de/c/api"
+	"zettelstore.de/c/maps"
+	"zettelstore.de/z/input"
+	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/id"
+)
+
+type keyUsage int
+
+const (
+	_             keyUsage = iota
+	usageUser              // Key will be manipulated by the user
+	usageComputed          // Key is computed by zettelstore
+	usageProperty          // Key is computed and not stored by zettelstore
+)
+
+// DescriptionKey formally describes each supported metadata key.
+type DescriptionKey struct {
+	Name    string
+	Type    *DescriptionType
+	usage   keyUsage
+	Inverse string
+}
+
+// IsComputed returns true, if metadata is computed and not set by the user.
+func (kd *DescriptionKey) IsComputed() bool { return kd.usage >= usageComputed }
+
+// IsProperty returns true, if metadata is a computed property.
+func (kd *DescriptionKey) IsProperty() bool { return kd.usage >= usageProperty }
+
+// IsStoredComputed retruns true, if metadata is computed, but also stored.
+func (kd *DescriptionKey) IsStoredComputed() bool { return kd.usage == usageComputed }
+
+var registeredKeys = make(map[string]*DescriptionKey)
+
+func registerKey(name string, t *DescriptionType, usage keyUsage, inverse string) {
+	if _, ok := registeredKeys[name]; ok {
+		panic("Key '" + name + "' already defined")
+	}
+	if inverse != "" {
+		if t != TypeID && t != TypeIDSet {
+			panic("Inversable key '" + name + "' is not identifier type, but " + t.String())
+		}
+		inv, ok := registeredKeys[inverse]
+		if !ok {
+			panic("Inverse Key '" + inverse + "' not found")
+		}
+		if !inv.IsComputed() {
+			panic("Inverse Key '" + inverse + "' is not computed.")
+		}
+		if inv.Type != TypeIDSet {
+			panic("Inverse Key '" + inverse + "' is not an identifier set, but " + inv.Type.String())
+		}
+	}
+	registeredKeys[name] = &DescriptionKey{name, t, usage, inverse}
+}
+
+// IsComputed returns true, if key denotes a computed metadata key.
+func IsComputed(name string) bool {
+	if kd, ok := registeredKeys[name]; ok {
+		return kd.IsComputed()
+	}
+	return false
+}
+
+// IsProperty returns true, if key denotes a property metadata value.
+func IsProperty(name string) bool {
+	if kd, ok := registeredKeys[name]; ok {
+		return kd.IsProperty()
+	}
+	return false
+}
+
+// Inverse returns the name of the inverse key.
+func Inverse(name string) string {
+	if kd, ok := registeredKeys[name]; ok {
+		return kd.Inverse
+	}
+	return ""
+}
+
+// GetDescription returns the key description object of the given key name.
+func GetDescription(name string) DescriptionKey {
+	if d, ok := registeredKeys[name]; ok {
+		return *d
+	}
+	return DescriptionKey{Type: Type(name)}
+}
+
+// GetSortedKeyDescriptions delivers all metadata key descriptions as a slice, sorted by name.
+func GetSortedKeyDescriptions() []*DescriptionKey {
+	keys := maps.Keys(registeredKeys)
+	result := make([]*DescriptionKey, 0, len(keys))
+	for _, n := range keys {
+		result = append(result, registeredKeys[n])
+	}
+	return result
+}
+
+// Supported keys.
+func init() {
+	registerKey(api.KeyID, TypeID, usageComputed, "")
+	registerKey(api.KeyTitle, TypeEmpty, usageUser, "")
+	registerKey(api.KeyRole, TypeWord, usageUser, "")
+	registerKey(api.KeyTags, TypeTagSet, usageUser, "")
+	registerKey(api.KeySyntax, TypeWord, usageUser, "")
+
+	// Properties that are inverse keys
+	registerKey(api.KeyFolge, TypeIDSet, usageProperty, "")
+	registerKey(api.KeySuccessors, TypeIDSet, usageProperty, "")
+	registerKey(api.KeySubordinates, TypeIDSet, usageProperty, "")
+
+	// Non-inverse keys
+	registerKey(api.KeyAuthor, TypeString, usageUser, "")
+	registerKey(api.KeyBack, TypeIDSet, usageProperty, "")
+	registerKey(api.KeyBackward, TypeIDSet, usageProperty, "")
+	registerKey(api.KeyBoxNumber, TypeNumber, usageProperty, "")
+	registerKey(api.KeyCopyright, TypeString, usageUser, "")
+	registerKey(api.KeyCreated, TypeTimestamp, usageComputed, "")
+	registerKey(api.KeyCredential, TypeCredential, usageUser, "")
+	registerKey(api.KeyDead, TypeIDSet, usageProperty, "")
+	registerKey(api.KeyExpire, TypeTimestamp, usageUser, "")
+	registerKey(api.KeyForward, TypeIDSet, usageProperty, "")
+	registerKey(api.KeyLang, TypeWord, usageUser, "")
+	registerKey(api.KeyLicense, TypeEmpty, usageUser, "")
+	registerKey(api.KeyModified, TypeTimestamp, usageComputed, "")
+	registerKey(api.KeyPrecursor, TypeIDSet, usageUser, api.KeyFolge)
+	registerKey(api.KeyPredecessor, TypeID, usageUser, api.KeySuccessors)
+	registerKey(api.KeyPublished, TypeTimestamp, usageProperty, "")
+	registerKey(api.KeyQuery, TypeEmpty, usageUser, "")
+	registerKey(api.KeyReadOnly, TypeWord, usageUser, "")
+	registerKey(api.KeySummary, TypeZettelmarkup, usageUser, "")
+	registerKey(api.KeySuperior, TypeIDSet, usageUser, api.KeySubordinates)
+	registerKey(api.KeyURL, TypeURL, usageUser, "")
+	registerKey(api.KeyUselessFiles, TypeString, usageProperty, "")
+	registerKey(api.KeyUserID, TypeWord, usageUser, "")
+	registerKey(api.KeyUserRole, TypeWord, usageUser, "")
+	registerKey(api.KeyVisibility, TypeWord, usageUser, "")
+}
+
+// NewPrefix is the prefix for metadata key in template zettel for creating new zettel.
+const NewPrefix = "new-"
+
+// Meta contains all meta-data of a zettel.
+type Meta struct {
+	Zid     id.Zid
+	pairs   map[string]string
+	YamlSep bool
+}
+
+// New creates a new chunk for storing metadata.
+func New(zid id.Zid) *Meta {
+	return &Meta{Zid: zid, pairs: make(map[string]string, 5)}
+}
+
+// NewWithData creates metadata object with given data.
+func NewWithData(zid id.Zid, data map[string]string) *Meta {
+	pairs := make(map[string]string, len(data))
+	for k, v := range data {
+		pairs[k] = v
+	}
+	return &Meta{Zid: zid, pairs: pairs}
+}
+
+// Length returns the number of bytes stored for the metadata.
+func (m *Meta) Length() int {
+	if m == nil {
+		return 0
+	}
+	result := 6 // storage needed for Zid
+	for k, v := range m.pairs {
+		result += len(k) + len(v) + 1 // 1 because separator
+	}
+	return result
+}
+
+// Clone returns a new copy of the metadata.
+func (m *Meta) Clone() *Meta {
+	return &Meta{
+		Zid:     m.Zid,
+		pairs:   m.Map(),
+		YamlSep: m.YamlSep,
+	}
+}
+
+// Map returns a copy of the meta data as a string map.
+func (m *Meta) Map() map[string]string {
+	pairs := make(map[string]string, len(m.pairs))
+	for k, v := range m.pairs {
+		pairs[k] = v
+	}
+	return pairs
+}
+
+var reKey = regexp.MustCompile("^[0-9a-z][-0-9a-z]{0,254}$")
+
+// KeyIsValid returns true, if the string is a valid metadata key.
+func KeyIsValid(s string) bool { return reKey.MatchString(s) }
+
+// Pair is one key-value-pair of a Zettel meta.
+type Pair struct {
+	Key   string
+	Value string
+}
+
+var firstKeys = []string{api.KeyTitle, api.KeyRole, api.KeyTags, api.KeySyntax}
+var firstKeySet strfun.Set
+
+func init() {
+	firstKeySet = strfun.NewSet(firstKeys...)
+}
+
+// Set stores the given string value under the given key.
+func (m *Meta) Set(key, value string) {
+	if key != api.KeyID {
+		m.pairs[key] = trimValue(value)
+	}
+}
+
+// SetNonEmpty stores the given value under the given key, if the value is non-empty.
+// An empty value will delete the previous association.
+func (m *Meta) SetNonEmpty(key, value string) {
+	if value == "" {
+		delete(m.pairs, key)
+	} else if key != api.KeyID {
+		m.pairs[key] = trimValue(value)
+	}
+}
+
+func trimValue(value string) string {
+	return strings.TrimFunc(value, input.IsSpace)
+}
+
+// Get retrieves the string value of a given key. The bool value signals,
+// whether there was a value stored or not.
+func (m *Meta) Get(key string) (string, bool) {
+	if m == nil {
+		return "", false
+	}
+	if key == api.KeyID {
+		return m.Zid.String(), true
+	}
+	value, ok := m.pairs[key]
+	return value, ok
+}
+
+// GetDefault retrieves the string value of the given key. If no value was
+// stored, the given default value is returned.
+func (m *Meta) GetDefault(key, def string) string {
+	if value, found := m.Get(key); found {
+		return value
+	}
+	return def
+}
+
+// GetTitle returns the title of the metadata. It is the only key that has a
+// defined default value: the string representation of the zettel identifier.
+func (m *Meta) GetTitle() string {
+	if title, found := m.Get(api.KeyTitle); found {
+		return title
+	}
+	return m.Zid.String()
+}
+
+// Pairs returns not computed key/values pairs stored, in a specific order.
+// First come the pairs with predefined keys: MetaTitleKey, MetaTagsKey, MetaSyntaxKey,
+// MetaContextKey. Then all other pairs are append to the list, ordered by key.
+func (m *Meta) Pairs() []Pair {
+	return m.doPairs(m.getFirstKeys(), notComputedKey)
+}
+
+// ComputedPairs returns all key/values pairs stored, in a specific order. First come
+// the pairs with predefined keys: MetaTitleKey, MetaTagsKey, MetaSyntaxKey,
+// MetaContextKey. Then all other pairs are append to the list, ordered by key.
+func (m *Meta) ComputedPairs() []Pair {
+	return m.doPairs(m.getFirstKeys(), anyKey)
+}
+
+// PairsRest returns not computed key/values pairs stored, except the values with
+// predefined keys. The pairs are ordered by key.
+func (m *Meta) PairsRest() []Pair {
+	result := make([]Pair, 0, len(m.pairs))
+	return m.doPairs(result, notComputedKey)
+}
+
+// ComputedPairsRest returns all key/values pairs stored, except the values with
+// predefined keys. The pairs are ordered by key.
+func (m *Meta) ComputedPairsRest() []Pair {
+	result := make([]Pair, 0, len(m.pairs))
+	return m.doPairs(result, anyKey)
+}
+
+func notComputedKey(key string) bool { return !IsComputed(key) }
+func anyKey(string) bool             { return true }
+
+func (m *Meta) doPairs(firstKeys []Pair, addKeyPred func(string) bool) []Pair {
+	keys := m.getKeysRest(addKeyPred)
+	for _, k := range keys {
+		firstKeys = append(firstKeys, Pair{k, m.pairs[k]})
+	}
+	return firstKeys
+}
+
+func (m *Meta) getFirstKeys() []Pair {
+	result := make([]Pair, 0, len(m.pairs))
+	for _, key := range firstKeys {
+		if value, ok := m.pairs[key]; ok {
+			result = append(result, Pair{key, value})
+		}
+	}
+	return result
+}
+
+func (m *Meta) getKeysRest(addKeyPred func(string) bool) []string {
+	keys := make([]string, 0, len(m.pairs))
+	for k := range m.pairs {
+		if !firstKeySet.Has(k) && addKeyPred(k) {
+			keys = append(keys, k)
+		}
+	}
+	sort.Strings(keys)
+	return keys
+}
+
+// Delete removes a key from the data.
+func (m *Meta) Delete(key string) {
+	if key != api.KeyID {
+		delete(m.pairs, key)
+	}
+}
+
+// Equal compares to metas for equality.
+func (m *Meta) Equal(o *Meta, allowComputed bool) bool {
+	if m == nil && o == nil {
+		return true
+	}
+	if m == nil || o == nil || m.Zid != o.Zid {
+		return false
+	}
+	tested := make(strfun.Set, len(m.pairs))
+	for k, v := range m.pairs {
+		tested.Set(k)
+		if !equalValue(k, v, o, allowComputed) {
+			return false
+		}
+	}
+	for k, v := range o.pairs {
+		if !tested.Has(k) && !equalValue(k, v, m, allowComputed) {
+			return false
+		}
+	}
+	return true
+}
+
+func equalValue(key, val string, other *Meta, allowComputed bool) bool {
+	if allowComputed || !IsComputed(key) {
+		if valO, found := other.pairs[key]; !found || val != valO {
+			return false
+		}
+	}
+	return true
+}
+
+// Sanitize all metadata keys and values, so that they can be written safely into a file.
+func (m *Meta) Sanitize() {
+	if m == nil {
+		return
+	}
+	for k, v := range m.pairs {
+		m.pairs[RemoveNonGraphic(k)] = RemoveNonGraphic(v)
+	}
+}
+
+// RemoveNonGraphic changes the given string not to include non-graphical characters.
+// It is needed to sanitize meta data.
+func RemoveNonGraphic(s string) string {
+	if s == "" {
+		return ""
+	}
+	pos := 0
+	var sb strings.Builder
+	for pos < len(s) {
+		nextPos := strings.IndexFunc(s[pos:], func(r rune) bool { return !unicode.IsGraphic(r) })
+		if nextPos < 0 {
+			break
+		}
+		sb.WriteString(s[pos:nextPos])
+		sb.WriteByte(' ')
+		_, size := utf8.DecodeRuneInString(s[nextPos:])
+		pos = nextPos + size
+	}
+	if pos == 0 {
+		return strings.TrimSpace(s)
+	}
+	sb.WriteString(s[pos:])
+	return strings.TrimSpace(sb.String())
+}

ADDED   zettel/meta/meta_test.go
Index: zettel/meta/meta_test.go
==================================================================
--- zettel/meta/meta_test.go
+++ zettel/meta/meta_test.go
@@ -0,0 +1,261 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package meta
+
+import (
+	"strings"
+	"testing"
+
+	"zettelstore.de/c/api"
+	"zettelstore.de/z/zettel/id"
+)
+
+const testID = id.Zid(98765432101234)
+
+func TestKeyIsValid(t *testing.T) {
+	t.Parallel()
+	validKeys := []string{"0", "a", "0-", "title", "title-----", strings.Repeat("r", 255)}
+	for _, key := range validKeys {
+		if !KeyIsValid(key) {
+			t.Errorf("Key %q wrongly identified as invalid key", key)
+		}
+	}
+	invalidKeys := []string{"", "-", "-a", "Title", "a_b", strings.Repeat("e", 256)}
+	for _, key := range invalidKeys {
+		if KeyIsValid(key) {
+			t.Errorf("Key %q wrongly identified as valid key", key)
+		}
+	}
+}
+
+func TestTitleHeader(t *testing.T) {
+	t.Parallel()
+	m := New(testID)
+	if got, ok := m.Get(api.KeyTitle); ok && got != "" {
+		t.Errorf("Title is not empty, but %q", got)
+	}
+	addToMeta(m, api.KeyTitle, " ")
+	if got, ok := m.Get(api.KeyTitle); ok && got != "" {
+		t.Errorf("Title is not empty, but %q", got)
+	}
+	const st = "A simple text"
+	addToMeta(m, api.KeyTitle, " "+st+"  ")
+	if got, ok := m.Get(api.KeyTitle); !ok || got != st {
+		t.Errorf("Title is not %q, but %q", st, got)
+	}
+	addToMeta(m, api.KeyTitle, "  "+st+"\t")
+	const exp = st + " " + st
+	if got, ok := m.Get(api.KeyTitle); !ok || got != exp {
+		t.Errorf("Title is not %q, but %q", exp, got)
+	}
+
+	m = New(testID)
+	const at = "A Title"
+	addToMeta(m, api.KeyTitle, at)
+	addToMeta(m, api.KeyTitle, " ")
+	if got, ok := m.Get(api.KeyTitle); !ok || got != at {
+		t.Errorf("Title is not %q, but %q", at, got)
+	}
+}
+
+func checkSet(t *testing.T, exp []string, m *Meta, key string) {
+	t.Helper()
+	got, _ := m.GetList(key)
+	for i, tag := range exp {
+		if i < len(got) {
+			if tag != got[i] {
+				t.Errorf("Pos=%d, expected %q, got %q", i, exp[i], got[i])
+			}
+		} else {
+			t.Errorf("Expected %q, but is missing", exp[i])
+		}
+	}
+	if len(exp) < len(got) {
+		t.Errorf("Extra tags: %q", got[len(exp):])
+	}
+}
+
+func TestTagsHeader(t *testing.T) {
+	t.Parallel()
+	m := New(testID)
+	checkSet(t, []string{}, m, api.KeyTags)
+
+	addToMeta(m, api.KeyTags, "")
+	checkSet(t, []string{}, m, api.KeyTags)
+
+	addToMeta(m, api.KeyTags, "  #t1 #t2  #t3 #t4  ")
+	checkSet(t, []string{"#t1", "#t2", "#t3", "#t4"}, m, api.KeyTags)
+
+	addToMeta(m, api.KeyTags, "#t5")
+	checkSet(t, []string{"#t1", "#t2", "#t3", "#t4", "#t5"}, m, api.KeyTags)
+
+	addToMeta(m, api.KeyTags, "t6")
+	checkSet(t, []string{"#t1", "#t2", "#t3", "#t4", "#t5"}, m, api.KeyTags)
+}
+
+func TestSyntax(t *testing.T) {
+	t.Parallel()
+	m := New(testID)
+	if got, ok := m.Get(api.KeySyntax); ok || got != "" {
+		t.Errorf("Syntax is not %q, but %q", "", got)
+	}
+	addToMeta(m, api.KeySyntax, " ")
+	if got, _ := m.Get(api.KeySyntax); got != "" {
+		t.Errorf("Syntax is not %q, but %q", "", got)
+	}
+	addToMeta(m, api.KeySyntax, "MarkDown")
+	const exp = "markdown"
+	if got, ok := m.Get(api.KeySyntax); !ok || got != exp {
+		t.Errorf("Syntax is not %q, but %q", exp, got)
+	}
+	addToMeta(m, api.KeySyntax, " ")
+	if got, _ := m.Get(api.KeySyntax); got != "" {
+		t.Errorf("Syntax is not %q, but %q", "", got)
+	}
+}
+
+func checkHeader(t *testing.T, exp map[string]string, gotP []Pair) {
+	t.Helper()
+	got := make(map[string]string, len(gotP))
+	for _, p := range gotP {
+		got[p.Key] = p.Value
+		if _, ok := exp[p.Key]; !ok {
+			t.Errorf("Key %q is not expected, but has value %q", p.Key, p.Value)
+		}
+	}
+	for k, v := range exp {
+		if gv, ok := got[k]; !ok || v != gv {
+			if ok {
+				t.Errorf("Key %q is not %q, but %q", k, v, got[k])
+			} else {
+				t.Errorf("Key %q missing, should have value %q", k, v)
+			}
+		}
+	}
+}
+
+func TestDefaultHeader(t *testing.T) {
+	t.Parallel()
+	m := New(testID)
+	addToMeta(m, "h1", "d1")
+	addToMeta(m, "H2", "D2")
+	addToMeta(m, "H1", "D1.1")
+	exp := map[string]string{"h1": "d1 D1.1", "h2": "D2"}
+	checkHeader(t, exp, m.Pairs())
+	addToMeta(m, "", "d0")
+	checkHeader(t, exp, m.Pairs())
+	addToMeta(m, "h3", "")
+	exp["h3"] = ""
+	checkHeader(t, exp, m.Pairs())
+	addToMeta(m, "h3", "  ")
+	checkHeader(t, exp, m.Pairs())
+	addToMeta(m, "h4", " ")
+	exp["h4"] = ""
+	checkHeader(t, exp, m.Pairs())
+}
+
+func TestDelete(t *testing.T) {
+	t.Parallel()
+	m := New(testID)
+	m.Set("key", "val")
+	if got, ok := m.Get("key"); !ok || got != "val" {
+		t.Errorf("Value != %q, got: %v/%q", "val", ok, got)
+	}
+	m.Set("key", "")
+	if got, ok := m.Get("key"); !ok || got != "" {
+		t.Errorf("Value != %q, got: %v/%q", "", ok, got)
+	}
+	m.Delete("key")
+	if got, ok := m.Get("key"); ok || got != "" {
+		t.Errorf("Value != %q, got: %v/%q", "", ok, got)
+	}
+}
+
+func TestEqual(t *testing.T) {
+	t.Parallel()
+	testcases := []struct {
+		pairs1, pairs2 []string
+		allowComputed  bool
+		exp            bool
+	}{
+		{nil, nil, true, true},
+		{nil, nil, false, true},
+		{[]string{"a", "a"}, nil, false, false},
+		{[]string{"a", "a"}, nil, true, false},
+		{[]string{api.KeyFolge, "0"}, nil, true, false},
+		{[]string{api.KeyFolge, "0"}, nil, false, true},
+		{[]string{api.KeyFolge, "0"}, []string{api.KeyFolge, "0"}, true, true},
+		{[]string{api.KeyFolge, "0"}, []string{api.KeyFolge, "0"}, false, true},
+	}
+	for i, tc := range testcases {
+		m1 := pairs2meta(tc.pairs1)
+		m2 := pairs2meta(tc.pairs2)
+		got := m1.Equal(m2, tc.allowComputed)
+		if tc.exp != got {
+			t.Errorf("%d: %v =?= %v: expected=%v, but got=%v", i, tc.pairs1, tc.pairs2, tc.exp, got)
+		}
+		got = m2.Equal(m1, tc.allowComputed)
+		if tc.exp != got {
+			t.Errorf("%d: %v =!= %v: expected=%v, but got=%v", i, tc.pairs1, tc.pairs2, tc.exp, got)
+		}
+	}
+
+	// Pathologic cases
+	var m1, m2 *Meta
+	if !m1.Equal(m2, true) {
+		t.Error("Nil metas should be treated equal")
+	}
+	m1 = New(testID)
+	if m1.Equal(m2, true) {
+		t.Error("Empty meta should not be equal to nil")
+	}
+	if m2.Equal(m1, true) {
+		t.Error("Nil meta should should not be equal to empty")
+	}
+	m2 = New(testID + 1)
+	if m1.Equal(m2, true) {
+		t.Error("Different ID should differentiate")
+	}
+	if m2.Equal(m1, true) {
+		t.Error("Different ID should differentiate")
+	}
+}
+
+func pairs2meta(pairs []string) *Meta {
+	m := New(testID)
+	for i := 0; i < len(pairs); i = i + 2 {
+		m.Set(pairs[i], pairs[i+1])
+	}
+	return m
+}
+
+func TestRemoveNonGraphic(t *testing.T) {
+	testCases := []struct {
+		inp string
+		exp string
+	}{
+		{"", ""},
+		{" ", ""},
+		{"a", "a"},
+		{"a ", "a"},
+		{"a b", "a b"},
+		{"\n", ""},
+		{"a\n", "a"},
+		{"a\nb", "a b"},
+		{"a\tb", "a b"},
+	}
+	for i, tc := range testCases {
+		got := RemoveNonGraphic(tc.inp)
+		if tc.exp != got {
+			t.Errorf("%q/%d: expected %q, but got %q", tc.inp, i, tc.exp, got)
+		}
+	}
+}

ADDED   zettel/meta/parse.go
Index: zettel/meta/parse.go
==================================================================
--- zettel/meta/parse.go
+++ zettel/meta/parse.go
@@ -0,0 +1,177 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package meta
+
+import (
+	"strings"
+
+	"zettelstore.de/c/api"
+	"zettelstore.de/c/maps"
+	"zettelstore.de/z/input"
+	"zettelstore.de/z/strfun"
+	"zettelstore.de/z/zettel/id"
+)
+
+// NewFromInput parses the meta data of a zettel.
+func NewFromInput(zid id.Zid, inp *input.Input) *Meta {
+	if inp.Ch == '-' && inp.PeekN(0) == '-' && inp.PeekN(1) == '-' {
+		skipToEOL(inp)
+		inp.EatEOL()
+	}
+	meta := New(zid)
+	for {
+		skipSpace(inp)
+		switch inp.Ch {
+		case '\r':
+			if inp.Peek() == '\n' {
+				inp.Next()
+			}
+			fallthrough
+		case '\n':
+			inp.Next()
+			return meta
+		case input.EOS:
+			return meta
+		case '%':
+			skipToEOL(inp)
+			inp.EatEOL()
+			continue
+		}
+		parseHeader(meta, inp)
+		if inp.Ch == '-' && inp.PeekN(0) == '-' && inp.PeekN(1) == '-' {
+			skipToEOL(inp)
+			inp.EatEOL()
+			meta.YamlSep = true
+			return meta
+		}
+	}
+}
+
+func parseHeader(m *Meta, inp *input.Input) {
+	pos := inp.Pos
+	for isHeader(inp.Ch) {
+		inp.Next()
+	}
+	key := inp.Src[pos:inp.Pos]
+	skipSpace(inp)
+	if inp.Ch == ':' {
+		inp.Next()
+	}
+	var val []byte
+	for {
+		skipSpace(inp)
+		pos = inp.Pos
+		skipToEOL(inp)
+		val = append(val, inp.Src[pos:inp.Pos]...)
+		inp.EatEOL()
+		if !input.IsSpace(inp.Ch) {
+			break
+		}
+		val = append(val, ' ')
+	}
+	addToMeta(m, string(key), string(val))
+}
+
+func skipSpace(inp *input.Input) {
+	for input.IsSpace(inp.Ch) {
+		inp.Next()
+	}
+}
+
+func skipToEOL(inp *input.Input) {
+	for {
+		switch inp.Ch {
+		case '\n', '\r', input.EOS:
+			return
+		}
+		inp.Next()
+	}
+}
+
+// Return true iff rune is valid for header key.
+func isHeader(ch rune) bool {
+	return ('a' <= ch && ch <= 'z') ||
+		('0' <= ch && ch <= '9') ||
+		ch == '-' ||
+		('A' <= ch && ch <= 'Z')
+}
+
+type predValidElem func(string) bool
+
+func addToSet(set strfun.Set, elems []string, useElem predValidElem) {
+	for _, s := range elems {
+		if len(s) > 0 && useElem(s) {
+			set.Set(s)
+		}
+	}
+}
+
+func addSet(m *Meta, key, val string, useElem predValidElem) {
+	newElems := strings.Fields(val)
+	oldElems, ok := m.GetList(key)
+	if !ok {
+		oldElems = nil
+	}
+
+	set := make(strfun.Set, len(newElems)+len(oldElems))
+	addToSet(set, newElems, useElem)
+	if len(set) == 0 {
+		// Nothing to add. Maybe because of rejected elements.
+		return
+	}
+	addToSet(set, oldElems, useElem)
+	m.SetList(key, maps.Keys(set))
+}
+
+func addData(m *Meta, k, v string) {
+	if o, ok := m.Get(k); !ok || o == "" {
+		m.Set(k, v)
+	} else if v != "" {
+		m.Set(k, o+" "+v)
+	}
+}
+
+func addToMeta(m *Meta, key, val string) {
+	v := trimValue(val)
+	key = strings.ToLower(key)
+	if !KeyIsValid(key) {
+		return
+	}
+	switch key {
+	case "", api.KeyID:
+		// Empty key and 'id' key will be ignored
+		return
+	}
+
+	switch Type(key) {
+	case TypeTagSet:
+		addSet(m, key, strings.ToLower(v), func(s string) bool { return s[0] == '#' && len(s) > 1 })
+	case TypeWord:
+		m.Set(key, strings.ToLower(v))
+	case TypeWordSet:
+		addSet(m, key, strings.ToLower(v), func(s string) bool { return true })
+	case TypeID:
+		if _, err := id.Parse(v); err == nil {
+			m.Set(key, v)
+		}
+	case TypeIDSet:
+		addSet(m, key, v, func(s string) bool {
+			_, err := id.Parse(s)
+			return err == nil
+		})
+	case TypeTimestamp:
+		if _, ok := TimeValue(v); ok {
+			m.Set(key, v)
+		}
+	default:
+		addData(m, key, v)
+	}
+}

ADDED   zettel/meta/parse_test.go
Index: zettel/meta/parse_test.go
==================================================================
--- zettel/meta/parse_test.go
+++ zettel/meta/parse_test.go
@@ -0,0 +1,167 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package meta_test
+
+import (
+	"strings"
+	"testing"
+
+	"zettelstore.de/c/api"
+	"zettelstore.de/z/input"
+	"zettelstore.de/z/zettel/meta"
+)
+
+func parseMetaStr(src string) *meta.Meta {
+	return meta.NewFromInput(testID, input.NewInput([]byte(src)))
+}
+
+func TestEmpty(t *testing.T) {
+	t.Parallel()
+	m := parseMetaStr("")
+	if got, ok := m.Get(api.KeySyntax); ok || got != "" {
+		t.Errorf("Syntax is not %q, but %q", "", got)
+	}
+	if got, ok := m.GetList(api.KeyTags); ok || len(got) > 0 {
+		t.Errorf("Tags are not nil, but %v", got)
+	}
+}
+
+func TestTitle(t *testing.T) {
+	t.Parallel()
+	td := []struct{ s, e string }{
+		{api.KeyTitle + ": a title", "a title"},
+		{api.KeyTitle + ": a\n\t title", "a title"},
+		{api.KeyTitle + ": a\n\t title\r\n  x", "a title x"},
+		{api.KeyTitle + " AbC", "AbC"},
+		{api.KeyTitle + " AbC\n ded", "AbC ded"},
+		{api.KeyTitle + ": o\ntitle: p", "o p"},
+		{api.KeyTitle + ": O\n\ntitle: P", "O"},
+		{api.KeyTitle + ": b\r\ntitle: c", "b c"},
+		{api.KeyTitle + ": B\r\n\r\ntitle: C", "B"},
+		{api.KeyTitle + ": r\rtitle: q", "r q"},
+		{api.KeyTitle + ": R\r\rtitle: Q", "R"},
+	}
+	for i, tc := range td {
+		m := parseMetaStr(tc.s)
+		if got, ok := m.Get(api.KeyTitle); !ok || got != tc.e {
+			t.Log(m)
+			t.Errorf("TC=%d: expected %q, got %q", i, tc.e, got)
+		}
+	}
+}
+
+func TestTags(t *testing.T) {
+	t.Parallel()
+	testcases := []struct {
+		src string
+		exp string
+	}{
+		{"", ""},
+		{api.KeyTags + ":", ""},
+		{api.KeyTags + ": c", ""},
+		{api.KeyTags + ": #", ""},
+		{api.KeyTags + ": #c", "c"},
+		{api.KeyTags + ": #c #", "c"},
+		{api.KeyTags + ": #c #b", "b c"},
+		{api.KeyTags + ": #c # #", "c"},
+		{api.KeyTags + ": #c # #b", "b c"},
+	}
+	for i, tc := range testcases {
+		m := parseMetaStr(tc.src)
+		tags, found := m.GetTags(api.KeyTags)
+		if !found {
+			if tc.exp != "" {
+				t.Errorf("%d / %q: no %s found", i, tc.src, api.KeyTags)
+			}
+			continue
+		}
+		if tc.exp == "" && len(tags) > 0 {
+			t.Errorf("%d / %q: expected no %s, but got %v", i, tc.src, api.KeyTags, tags)
+			continue
+		}
+		got := strings.Join(tags, " ")
+		if tc.exp != got {
+			t.Errorf("%d / %q: expected %q, got: %q", i, tc.src, tc.exp, got)
+		}
+	}
+}
+
+func TestNewFromInput(t *testing.T) {
+	t.Parallel()
+	testcases := []struct {
+		input string
+		exp   []meta.Pair
+	}{
+		{"", []meta.Pair{}},
+		{" a:b", []meta.Pair{{"a", "b"}}},
+		{"%a:b", []meta.Pair{}},
+		{"a:b\r\n\r\nc:d", []meta.Pair{{"a", "b"}}},
+		{"a:b\r\n%c:d", []meta.Pair{{"a", "b"}}},
+		{"% a:b\r\n c:d", []meta.Pair{{"c", "d"}}},
+		{"---\r\na:b\r\n", []meta.Pair{{"a", "b"}}},
+		{"---\r\na:b\r\n--\r\nc:d", []meta.Pair{{"a", "b"}, {"c", "d"}}},
+		{"---\r\na:b\r\n---\r\nc:d", []meta.Pair{{"a", "b"}}},
+		{"---\r\na:b\r\n----\r\nc:d", []meta.Pair{{"a", "b"}}},
+		{"new-title:\nnew-url:", []meta.Pair{{"new-title", ""}, {"new-url", ""}}},
+	}
+	for i, tc := range testcases {
+		meta := parseMetaStr(tc.input)
+		if got := meta.Pairs(); !equalPairs(tc.exp, got) {
+			t.Errorf("TC=%d: expected=%v, got=%v", i, tc.exp, got)
+		}
+	}
+
+	// Test, whether input position is correct.
+	inp := input.NewInput([]byte("---\na:b\n---\nX"))
+	m := meta.NewFromInput(testID, inp)
+	exp := []meta.Pair{{"a", "b"}}
+	if got := m.Pairs(); !equalPairs(exp, got) {
+		t.Errorf("Expected=%v, got=%v", exp, got)
+	}
+	expCh := 'X'
+	if gotCh := inp.Ch; gotCh != expCh {
+		t.Errorf("Expected=%v, got=%v", expCh, gotCh)
+	}
+}
+
+func equalPairs(one, two []meta.Pair) bool {
+	if len(one) != len(two) {
+		return false
+	}
+	for i := 0; i < len(one); i++ {
+		if one[i].Key != two[i].Key || one[i].Value != two[i].Value {
+			return false
+		}
+	}
+	return true
+}
+
+func TestPrecursorIDSet(t *testing.T) {
+	t.Parallel()
+	var testdata = []struct {
+		inp string
+		exp string
+	}{
+		{"", ""},
+		{"123", ""},
+		{"12345678901234", "12345678901234"},
+		{"123 12345678901234", "12345678901234"},
+		{"12345678901234 123", "12345678901234"},
+		{"01234567890123 123 12345678901234", "01234567890123 12345678901234"},
+		{"12345678901234 01234567890123", "01234567890123 12345678901234"},
+	}
+	for i, tc := range testdata {
+		m := parseMetaStr(api.KeyPrecursor + ": " + tc.inp)
+		if got, ok := m.Get(api.KeyPrecursor); (!ok && tc.exp != "") || tc.exp != got {
+			t.Errorf("TC=%d: expected %q, but got %q when parsing %q", i, tc.exp, got, tc.inp)
+		}
+	}
+}

ADDED   zettel/meta/type.go
Index: zettel/meta/type.go
==================================================================
--- zettel/meta/type.go
+++ zettel/meta/type.go
@@ -0,0 +1,200 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package meta
+
+import (
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"zettelstore.de/c/api"
+	"zettelstore.de/z/zettel/id"
+)
+
+// DescriptionType is a description of a specific key type.
+type DescriptionType struct {
+	Name  string
+	IsSet bool
+}
+
+// String returns the string representation of the given type
+func (t DescriptionType) String() string { return t.Name }
+
+var registeredTypes = make(map[string]*DescriptionType)
+
+func registerType(name string, isSet bool) *DescriptionType {
+	if _, ok := registeredTypes[name]; ok {
+		panic("Type '" + name + "' already registered")
+	}
+	t := &DescriptionType{name, isSet}
+	registeredTypes[name] = t
+	return t
+}
+
+// Supported key types.
+var (
+	TypeCredential   = registerType(api.MetaCredential, false)
+	TypeEmpty        = registerType(api.MetaEmpty, false)
+	TypeID           = registerType(api.MetaID, false)
+	TypeIDSet        = registerType(api.MetaIDSet, true)
+	TypeNumber       = registerType(api.MetaNumber, false)
+	TypeString       = registerType(api.MetaString, false)
+	TypeTagSet       = registerType(api.MetaTagSet, true)
+	TypeTimestamp    = registerType(api.MetaTimestamp, false)
+	TypeURL          = registerType(api.MetaURL, false)
+	TypeWord         = registerType(api.MetaWord, false)
+	TypeWordSet      = registerType(api.MetaWordSet, true)
+	TypeZettelmarkup = registerType(api.MetaZettelmarkup, false)
+)
+
+// Type returns a type hint for the given key. If no type hint is specified,
+// TypeUnknown is returned.
+func (*Meta) Type(key string) *DescriptionType {
+	return Type(key)
+}
+
+var (
+	cachedTypedKeys = make(map[string]*DescriptionType)
+	mxTypedKey      sync.RWMutex
+	suffixTypes     = map[string]*DescriptionType{
+		"-date":   TypeTimestamp,
+		"-number": TypeNumber,
+		"-role":   TypeWord,
+		"-set":    TypeWordSet,
+		"-time":   TypeTimestamp,
+		"-title":  TypeZettelmarkup,
+		"-url":    TypeURL,
+		"-zettel": TypeID,
+		"-zid":    TypeID,
+		"-zids":   TypeIDSet,
+	}
+)
+
+// Type returns a type hint for the given key. If no type hint is specified,
+// TypeEmpty is returned.
+func Type(key string) *DescriptionType {
+	if k, ok := registeredKeys[key]; ok {
+		return k.Type
+	}
+	mxTypedKey.RLock()
+	k, ok := cachedTypedKeys[key]
+	mxTypedKey.RUnlock()
+	if ok {
+		return k
+	}
+	for suffix, t := range suffixTypes {
+		if strings.HasSuffix(key, suffix) {
+			mxTypedKey.Lock()
+			defer mxTypedKey.Unlock()
+			cachedTypedKeys[key] = t
+			return t
+		}
+	}
+	return TypeEmpty
+}
+
+// SetList stores the given string list value under the given key.
+func (m *Meta) SetList(key string, values []string) {
+	if key != api.KeyID {
+		for i, val := range values {
+			values[i] = trimValue(val)
+		}
+		m.pairs[key] = strings.Join(values, " ")
+	}
+}
+
+// SetNow stores the current timestamp under the given key.
+func (m *Meta) SetNow(key string) {
+	m.Set(key, time.Now().Local().Format(id.ZidLayout))
+}
+
+// BoolValue returns the value interpreted as a bool.
+func BoolValue(value string) bool {
+	if len(value) > 0 {
+		switch value[0] {
+		case '0', 'f', 'F', 'n', 'N':
+			return false
+		}
+	}
+	return true
+}
+
+// GetBool returns the boolean value of the given key.
+func (m *Meta) GetBool(key string) bool {
+	if value, ok := m.Get(key); ok {
+		return BoolValue(value)
+	}
+	return false
+}
+
+// TimeValue returns the time value of the given value.
+func TimeValue(value string) (time.Time, bool) {
+	if t, err := time.Parse(id.ZidLayout, value); err == nil {
+		return t, true
+	}
+	return time.Time{}, false
+}
+
+// GetTime returns the time value of the given key.
+func (m *Meta) GetTime(key string) (time.Time, bool) {
+	if value, ok := m.Get(key); ok {
+		return TimeValue(value)
+	}
+	return time.Time{}, false
+}
+
+// ListFromValue transforms a string value into a list value.
+func ListFromValue(value string) []string {
+	return strings.Fields(value)
+}
+
+// GetList retrieves the string list value of a given key. The bool value
+// signals, whether there was a value stored or not.
+func (m *Meta) GetList(key string) ([]string, bool) {
+	value, ok := m.Get(key)
+	if !ok {
+		return nil, false
+	}
+	return ListFromValue(value), true
+}
+
+// GetTags returns the list of tags as a string list. Each tag does not begin
+// with the '#' character, in contrast to `GetList`.
+func (m *Meta) GetTags(key string) ([]string, bool) {
+	tagsValue, ok := m.Get(key)
+	if !ok {
+		return nil, false
+	}
+	tags := ListFromValue(strings.ToLower(tagsValue))
+	for i, tag := range tags {
+		tags[i] = CleanTag(tag)
+	}
+	return tags, len(tags) > 0
+}
+
+// CleanTag removes the number character ('#') from a tag value and lowercases it.
+func CleanTag(tag string) string {
+	if len(tag) > 1 && tag[0] == '#' {
+		return tag[1:]
+	}
+	return tag
+}
+
+// GetNumber retrieves the numeric value of a given key.
+func (m *Meta) GetNumber(key string, def int64) int64 {
+	if value, ok := m.Get(key); ok {
+		if num, err := strconv.ParseInt(value, 10, 64); err == nil {
+			return num
+		}
+	}
+	return def
+}

ADDED   zettel/meta/type_test.go
Index: zettel/meta/type_test.go
==================================================================
--- zettel/meta/type_test.go
+++ zettel/meta/type_test.go
@@ -0,0 +1,64 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package meta_test
+
+import (
+	"strconv"
+	"testing"
+	"time"
+
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
+)
+
+func TestNow(t *testing.T) {
+	t.Parallel()
+	m := meta.New(id.Invalid)
+	m.SetNow("key")
+	val, ok := m.Get("key")
+	if !ok {
+		t.Error("Unable to get value of key")
+	}
+	if len(val) != 14 {
+		t.Errorf("Value is not 14 digits long: %q", val)
+	}
+	if _, err := strconv.ParseInt(val, 10, 64); err != nil {
+		t.Errorf("Unable to parse %q as an int64: %v", val, err)
+	}
+	if _, ok = m.GetTime("key"); !ok {
+		t.Errorf("Unable to get time from value %q", val)
+	}
+}
+
+func TestGetTime(t *testing.T) {
+	t.Parallel()
+	testCases := []struct {
+		value string
+		valid bool
+		exp   time.Time
+	}{
+		{"", false, time.Time{}},
+		{"1", false, time.Time{}},
+		{"00000000000000", false, time.Time{}},
+		{"98765432109876", false, time.Time{}},
+		{"20201221111905", true, time.Date(2020, time.December, 21, 11, 19, 5, 0, time.UTC)},
+	}
+	for i, tc := range testCases {
+		got, ok := meta.TimeValue(tc.value)
+		if ok != tc.valid {
+			t.Errorf("%d: parsing of %q should be %v, but got %v", i, tc.value, tc.valid, ok)
+			continue
+		}
+		if got != tc.exp {
+			t.Errorf("%d: parsing of %q should return %v, but got %v", i, tc.value, tc.exp, got)
+		}
+	}
+}

ADDED   zettel/meta/values.go
Index: zettel/meta/values.go
==================================================================
--- zettel/meta/values.go
+++ zettel/meta/values.go
@@ -0,0 +1,111 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package meta
+
+import (
+	"fmt"
+
+	"zettelstore.de/c/api"
+)
+
+// Supported syntax values.
+const (
+	SyntaxCSS      = api.ValueSyntaxCSS
+	SyntaxDraw     = api.ValueSyntaxDraw
+	SyntaxGif      = api.ValueSyntaxGif
+	SyntaxHTML     = api.ValueSyntaxHTML
+	SyntaxJPEG     = "jpeg"
+	SyntaxJPG      = "jpg"
+	SyntaxMarkdown = api.ValueSyntaxMarkdown
+	SyntaxMD       = api.ValueSyntaxMD
+	SyntaxMustache = api.ValueSyntaxMustache
+	SyntaxNone     = api.ValueSyntaxNone
+	SyntaxPlain    = "plain"
+	SyntaxPNG      = "png"
+	SyntaxSVG      = api.ValueSyntaxSVG
+	SyntaxSxn      = api.ValueSyntaxSxn
+	SyntaxText     = api.ValueSyntaxText
+	SyntaxTxt      = "txt"
+	SyntaxWebp     = "webp"
+	SyntaxZmk      = api.ValueSyntaxZmk
+)
+
+// Visibility enumerates the variations of the 'visibility' meta key.
+type Visibility int
+
+// Supported values for visibility.
+const (
+	_ Visibility = iota
+	VisibilityUnknown
+	VisibilityPublic
+	VisibilityCreator
+	VisibilityLogin
+	VisibilityOwner
+	VisibilityExpert
+)
+
+var visMap = map[string]Visibility{
+	api.ValueVisibilityPublic:  VisibilityPublic,
+	api.ValueVisibilityCreator: VisibilityCreator,
+	api.ValueVisibilityLogin:   VisibilityLogin,
+	api.ValueVisibilityOwner:   VisibilityOwner,
+	api.ValueVisibilityExpert:  VisibilityExpert,
+}
+var revVisMap = map[Visibility]string{}
+
+func init() {
+	for k, v := range visMap {
+		revVisMap[v] = k
+	}
+}
+
+// GetVisibility returns the visibility value of the given string
+func GetVisibility(val string) Visibility {
+	if vis, ok := visMap[val]; ok {
+		return vis
+	}
+	return VisibilityUnknown
+}
+
+func (v Visibility) String() string {
+	if s, ok := revVisMap[v]; ok {
+		return s
+	}
+	return fmt.Sprintf("Unknown (%d)", v)
+}
+
+// UserRole enumerates the supported values of meta key 'user-role'.
+type UserRole int
+
+// Supported values for user roles.
+const (
+	_ UserRole = iota
+	UserRoleUnknown
+	UserRoleCreator
+	UserRoleReader
+	UserRoleWriter
+	UserRoleOwner
+)
+
+var urMap = map[string]UserRole{
+	api.ValueUserRoleCreator: UserRoleCreator,
+	api.ValueUserRoleReader:  UserRoleReader,
+	api.ValueUserRoleWriter:  UserRoleWriter,
+	api.ValueUserRoleOwner:   UserRoleOwner,
+}
+
+// GetUserRole role returns the user role of the given string.
+func GetUserRole(val string) UserRole {
+	if ur, ok := urMap[val]; ok {
+		return ur
+	}
+	return UserRoleUnknown
+}

ADDED   zettel/meta/write.go
Index: zettel/meta/write.go
==================================================================
--- zettel/meta/write.go
+++ zettel/meta/write.go
@@ -0,0 +1,57 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package meta
+
+import "io"
+
+// Write writes metadata to a writer, excluding computed and propery values.
+func (m *Meta) Write(w io.Writer) (int, error) {
+	return m.doWrite(w, IsComputed)
+}
+
+// WriteComputed writes metadata to a writer, including computed values,
+// but excluding property values.
+func (m *Meta) WriteComputed(w io.Writer) (int, error) {
+	return m.doWrite(w, IsProperty)
+}
+
+func (m *Meta) doWrite(w io.Writer, ignoreKeyPred func(string) bool) (length int, err error) {
+	for _, p := range m.ComputedPairs() {
+		key := p.Key
+		if ignoreKeyPred(key) {
+			continue
+		}
+		if err != nil {
+			break
+		}
+		var l int
+		l, err = io.WriteString(w, key)
+		length += l
+		if err == nil {
+			l, err = w.Write(colonSpace)
+			length += l
+		}
+		if err == nil {
+			l, err = io.WriteString(w, p.Value)
+			length += l
+		}
+		if err == nil {
+			l, err = w.Write(newline)
+			length += l
+		}
+	}
+	return length, err
+}
+
+var (
+	colonSpace = []byte{':', ' '}
+	newline    = []byte{'\n'}
+)

ADDED   zettel/meta/write_test.go
Index: zettel/meta/write_test.go
==================================================================
--- zettel/meta/write_test.go
+++ zettel/meta/write_test.go
@@ -0,0 +1,57 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+package meta_test
+
+import (
+	"strings"
+	"testing"
+
+	"zettelstore.de/c/api"
+	"zettelstore.de/z/zettel/id"
+	"zettelstore.de/z/zettel/meta"
+)
+
+const testID = id.Zid(98765432101234)
+
+func newMeta(title string, tags []string, syntax string) *meta.Meta {
+	m := meta.New(testID)
+	if title != "" {
+		m.Set(api.KeyTitle, title)
+	}
+	if tags != nil {
+		m.Set(api.KeyTags, strings.Join(tags, " "))
+	}
+	if syntax != "" {
+		m.Set(api.KeySyntax, syntax)
+	}
+	return m
+}
+func assertWriteMeta(t *testing.T, m *meta.Meta, expected string) {
+	t.Helper()
+	var sb strings.Builder
+	m.Write(&sb)
+	if got := sb.String(); got != expected {
+		t.Errorf("\nExp: %q\ngot: %q", expected, got)
+	}
+}
+
+func TestWriteMeta(t *testing.T) {
+	t.Parallel()
+	assertWriteMeta(t, newMeta("", nil, ""), "")
+
+	m := newMeta("TITLE", []string{"#t1", "#t2"}, "syntax")
+	assertWriteMeta(t, m, "title: TITLE\ntags: #t1 #t2\nsyntax: syntax\n")
+
+	m = newMeta("TITLE", nil, "")
+	m.Set("user", "zettel")
+	m.Set("auth", "basic")
+	assertWriteMeta(t, m, "title: TITLE\nauth: basic\nuser: zettel\n")
+}

ADDED   zettel/zettel.go
Index: zettel/zettel.go
==================================================================
--- zettel/zettel.go
+++ zettel/zettel.go
@@ -0,0 +1,29 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2020-present Detlef Stern
+//
+// This file is part of Zettelstore.
+//
+// Zettelstore is licensed under the latest version of the EUPL (European Union
+// Public License). Please see file LICENSE.txt for your rights and obligations
+// under this license.
+//-----------------------------------------------------------------------------
+
+// Package zettel provides specific types, constants, and functions for zettel.
+package zettel
+
+import "zettelstore.de/z/zettel/meta"
+
+// Zettel is the main data object of a zettelstore.
+type Zettel struct {
+	Meta    *meta.Meta // Some additional meta-data.
+	Content Content    // The content of the zettel itself.
+}
+
+// Length returns the number of bytes to store the zettel (in a zettel view,
+// not in a technical view).
+func (z Zettel) Length() int { return z.Meta.Length() + z.Content.Length() }
+
+// Equal compares two zettel for equality.
+func (z Zettel) Equal(o Zettel, allowComputed bool) bool {
+	return z.Meta.Equal(o.Meta, allowComputed) && z.Content.Equal(&o.Content)
+}