I want to restrict users on my mediawiki
(http://wikipedia.sourceforge.net/) installation to only editing
specific sections of the wiki. I think the file to edit is
includes\EditPage.php

I want it to work so that  if a person's username contains a colon
(e.g. FOO:Bob) then they can only edit and create pages that are in
the form FOO:Page_Name, FOO:Main_Page etc. I want it to treat users
with usernames that don't contain a colon normally. E.g.

1) Someone with the username FOO:Bob can edit FOO:Page_Name but not
BAR:Main_Page.

2) Someone with the username Bob can edit FOO:Page_Name and BAR:Main_Page
and Main_Page

I'm happy for this edit to take the form of an edit converting "you
must login to edit this page" to "you must login and have the right
permissions to edit this page". I think that EditPage.php would need
to be edited twice in the areas containing the text:

if ( !$wgUser->getID() && $wgWhitelistEdit ) {
        $this->userNotLoggedInPage();
        return;
}

I have sought an answer to this question for a while and posted in
various other forua without success.