For every zettel you can specify under which condition the zettel is visible to others.
This is controlled with the metadata key [[''visibility''|00001006020000#visibility]].
The following values are supported:
; [!public|""public""]
: The zettel is visible to everybody, even if the user is not authenticated.
; [!login|""login""]
: Only an authenticated user can access the zettel.

  This is the default value for [[''default-visibility''|00001004020000#default-visibility]].
; [!creator|""creator""]
: Only an authenticated user that is allowed to create new zettel can access the zettel.
; [!owner|""owner""]
: Only the owner of the Zettelstore can access the zettel.

  This is for zettel with sensitive content, e.g. the [[configuration zettel|00001004020000]] or the various zettel that contains the templates for rendering zettel in HTML.
; [!expert|""expert""]
: Only the owner of the Zettelstore can access the zettel, if runtime configuration [[''expert-mode''|00001004020000#expert-mode]] is set to a [[boolean true value|00001006030500]].

  This is for zettel with sensitive content that might irritate the owner.
Computed zettel with internal runtime information are examples for such a zettel.
When you install a Zettelstore, only [[some zettel|query:visibility:public]] have visibility ""public"".
One is the zettel that contains [[CSS|00000000020001]] for displaying the [[web user interface|00001014000000]].
This is to ensure that the web interface looks nice even for not authenticated users.
Another is the zettel containing the Zettelstore [[license|00000000000004]].
The [[default image|00000000040001]], used if an image reference is invalid, is also public visible.

Please note: if [[authentication is not enabled|00001010040100]], every user has the same rights as the owner of a Zettelstore.
This is also true, if the Zettelstore runs additionally in [[read-only mode|00001004010000#read-only-mode]].
In this case, the [[runtime configuration zettel|00001004020000]] is shown (its visibility is ""owner"").
The [[startup configuration|00001004010000]] is not shown, because the associated computed zettel with identifier ''00000000000096'' is stored with the visibility ""expert"".
If you want to show such a zettel, you must set ''expert-mode'' to true.
=== Examples
By using a [[query expression|00001007700000]], you can easily create a zettel list based on the ''visibility'' metadata key:
|public|[[visibility:public|query:visibility:public]]
|login|[[visibility:login|query:visibility:login]]
|creator|[[visibility:creator|query:visibility:creator]]
|owner|[[visibility:owner|query:visibility:owner]]
|expert|[[visibility:expert|query:visibility:expert]][^Only if [[''expert-mode''|00001004020000#expert-mode]] is enabled, this list will show some zettel.]