that would be a mod..
i did this for a customer of min ( http://ctfisherman.com
).. i called it -- Teaser Topics
which is basically the same idea as a Teaser Forum, but extended down to the topic level.
the practical use was for a fishing forum where members of the 'elite' group would post fishing reports that they didn't want regular members to see..
fishing spots are kinda sacred in a way...