I want to limit the amount of membergroups one can join to 5. That said, there are a few groups that shouldn't be counted (staff groups) that I put into their secondary groups.
I was thinking of just having a counter and then hiding the join link when it reached 5 on the group membership page (?action=profile;area=groupmembership;u=1). I can't see anywhere else members can join these groups and I'm not worried about adding groups through profiles since only I can do that. If it could throw an error if you try to use a url to join a group when the count is 5+ that would be a bonus but I'm not sure I am worried about that, at this stage.