This subroutine unregisters a previously registered special page. Admittedly, this function is probably not very useful, except if you wish to unregister the built-in special pages (RecentChanges, and discussion pages). There could be certain cases where you would want to unregister a special page that was registered by another plugin, or perhaps there may be some toggle integrated with an admin page your plugin provides. None the less, it was decided that since a function exists to register a special page, there should also be a clean and easy way to later unregister it.
PageName - This will be the name of the page you wish to unregister. If the page name was previously registered, Aneuch will unregister it, and no longer call the subroutine associated with the page when it is loaded.
This function is not called in the Aneuch source anywhere, however this is being provided as an example for plugin developers.
This will unregister the page 'RecentChanges', which by default is set to call DoRecentChanges every time the page is loaded. If you use this command in your plugin, then every time someone visits the page RecentChanges, they will not actually see the list of recent changes to the site.