'UserGetLanguageObject': Called when getting user's interface language object.
$user: User object
&$code: Language code that will be used to create the object
-$context: RequestContext object
+$context: IContextSource object
'UserGetReservedNames': Allows to modify $wgReservedUsernames at run time.
&$reservedUsernames: $wgReservedUsernames
$to: Array of MailAddress objects for the recipients
&$returnPath: The return address string
+'LoginFormValidErrorMessages': Called in LoginForm when a function gets valid error
+messages. Allows to add additional error messages (except messages already in
+LoginForm::$validErrorMessages).
+&$messages Already added messages (inclusive messages from LoginForm::$validErrorMessages)
+
'WantedPages::getQueryInfo': Called in WantedPagesPage::getQueryInfo(), can be
used to alter the SQL query which gets the list of wanted pages.
&$wantedPages: WantedPagesPage object