title: Encoding of Sz Metadata
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
back: 00001012931000
backward: 00001012931000
box-number: 1
copyright: (c) 2020-present by Detlef Stern <ds@zettelstore.de>
created: 20230403161618
forward: 00001006030000 00001006031000 00001006031500 00001006032000 00001006032500 00001006033000 00001006033500 00001006034000 00001006034500 00001006035000 00001006035500
lang: en
license: EUPL-1.2-or-later
modified: 20250115172406
published: 20250115172406
visibility: public

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 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''|<ListValue
|<[[Number|00001006033000]]|<''NUMBER''|<string
|<[[String|00001006033500]]|<''STRING''|<string
|<[[TagSet|00001006034000]]|<''TAG-SET''|<ListValue
|<[[Timestamp|00001006034500]]|<''TIMESTAMP''|<string
|<[[URL|00001006035000]]|<''URL''|<string
|<[[Word|00001006035500]]|<''WORD''|<string
:::{="syntax"}
__ListValue__ **=** ''('' String,,1,, String,,2,, … String,,n,, '')''.
:::
Examples:
* The title of this zettel is represented as: ''(EMPTY-STRING title "Encoding of Sz Metadata")''
* The tags of this zettel are represented as: ''(TAG-SET tags ("#api" "#manual" "#reference" "#zettelstore"))''