MediaWiki talk:Sitenotice

MediaWiki:Sitenotice is displayed above the page title for all users, unless it is superseded by another notice.

The message is displayed if it is defined. 'Defined' means the sitenotice has content more than a 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 $wgSiteNotice 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.

http://www.mediawiki.org/wiki/Sitenotice