Details

$wgSpecialPages stores a list of custom special pages defined for a MediaWiki installation. The array is keyed by a non-localized id for the special page. The value assigned to each key is an ObjectFactory specifier (MediaWiki 1.34+), or one of the following:

• string: a string containing the name of a subclass of SpecialPage .
• array: an array where the first element is the name of the subclass and all remaining elements are parameters that should be passed to the constructor of that subclass. ( This format was deprecated in MW 1.18 and is no longer recognized as of MW 1.32.)
• callback: since MW 1.24, Gerrit change 152755 expected to return a SpecialPage instance. Useful for full control over the special page's construction parameters.
• an actual SpecialPage object. (deprecated in 1.34)

A special page can also be disabled by using:

$wgSpecialPages['Name'] = DisabledSpecialPage::getCallback( 'Name', 'message' );

For more information, please see SpecialPage.php