Can a thread be made semi private?

In other words, can I make a thread in my game and have only john and joe and Jill in it?

I tried thru the admin panel, but had no wait to add players.

At this time, you cannot limit access to threads, only to forums. That's not a native functionality in any forums I've come across, so I never considered it, but I've been told some other PbP sites have this feature, so I'm considering adding it, but its not terribly high on the priority list right now.