Manual:Interface/Sitenotice

MediaWiki:Sitenotice is displayed above the page title for all users if it is defined, unless it is superseded by another notice. 'Defined' means it exists and has content other than the single character '-'.

Which notice is displayed for a user is decided in this order:
 * 1) If the CentralNotice extension is enabled, it is displayed (even if not defined); see below.
 * 2) If the user is anonymous, MediaWiki:Anonnotice is displayed (if defined).
 * 3) Otherwise, MediaWiki:Sitenotice is displayed (if defined).
 * 4) Otherwise, the global notice in CommonSettings.php is displayed (if defined).
 * 5) Otherwise, no notice is displayed.

Registered users can hide the site notice by clicking "[dismiss]". To show the site notice again for those users, increment the number in MediaWiki:Sitenotice id.

CentralNotice
The CentralNotice extension customized for the Wikimedia Foundation supersedes all other notices. The messages are edited through the pages listed at m:Special:Prefixindex/MediaWiki:Centralnotice.