MyBB Community Forums

Is it possible to allow a user to be in only one group at a time?

For instance, JoeBob123 is a part of GroupA.
He signs up to be part of GroupB.
Now JoeBob123 is part of GroupB, and not part of GroupA automatically.

Unfortunately, you'd need a code modification for this, assuming you wanted that exact behaviour.

I dont neccessarily need that exact behaviour. Another way that would be ok would be if the user was required to leave his/her current group before joining a new one. Can this be set up without modification?

EDIT: If it's not, how hard would it be to modify to be like that?