This will register a "special page." It allows you to associate a subroutine with a page name. Every time the page you associate is loaded by Aneuch, whether or not the page actually exists in the database, the associated subroutine is called. The output of the subroutine, if any, is appended to the bottom of the existing page content (if any).
This is used internally by Aneuch to show recent changes, and to handle the discussion pages (see Examples below).
PageName - This is a required option. Pass the name of a page here, or optionally you can use a regex here to match all pages with a certain pattern.
Subroutine - This should be the subroutine that is called when the page name you specify is loaded. Must be entered in this format: \&SubroutineName
These are actual examples from the Aneuch source code:
This registers the page 'RecentChanges', and will call the subroutine DoRecentChanges every time the page is loaded.
This registers any page which begins with $DiscussPrefix, which defaults to 'Discuss_', and will call the subroutine DoDiscuss every time one of these pages is loaded.