I posted this last year, but a refresher:
It’s pretty simple. Be nice to me, and be nice to your fellow posters. Don’t use extreme profanity. Don’t make comments slandering entire groups of people. Use common sense. Basically, treat this forum like a civilized conversation. Don’t write anything you wouldn’t want your mother to hear you say.
There is one judge, me. (Unless Merv thinks I’ve let things get out of hand.) Everyone gets one warning. On the second offense, you’re banned. You can appeal to me via email but insulting the judge is a very bad way to get him to agree with you.
I didn’t want to do this, but I also don’t want this site to go the way of Usenet, or Metafilter, or Little Green Footballs, or (name your own online forum that’s been taken over by barbarians).
I will add one new point, or rather reinforce the first sentences. Be civilized, and do not attack other posters personally. I’d like everyone to think first. Would you speak aloud to another individual what you’re writing? If not, you probably shouldn’t write it.