Our homeschool group has one unusual rule (at least in my experience): petty griping behind the back of the organizer for an event is strictly forbidden. I mean strictly. Like you get one warning and then you're out of the group. If you have a problem, you are required to address it with the person handling things. Period. If it's not a serious enough issue to talk to the planner about it, then it's not serious enough to talk about behind her back.
That and the strict RSVP rule (also one warning and out if you break it) are really the only two rules, but they're good ones. I strongly suspect that they're the reason our group is extremely kind to one another and yet still runs like a German clock!
Of course, I am an INTJ/Spock on the Meyers-Briggs personality test, so I WOULD like rules like those...
