Let's face it, all forums or most forums have a set of rules that their members need to follow. That being said, for your forums, what rules are always incorporated into your projects? For me, I do not allow spamming at all. Actually, my staff is asked to automatically ban a user for spamming on the forum as we have a zero tolerance policy for it. Another frequent rule is that threats of violence and death, stalking, etc. are prohibited on any of my sites. If a user is caught doing any of those things, not only are they banned, but the authorities are notified to cover my own butt in case an incident is reported to me and a user actually gets hurt.