On some others forums I've participated in, in the past one site rule I found quite refreshing, was the prohibition of "goodbye threads". It worked like this...
The rule was laid out to all, that no "goodbye threads were permitted. And if someone so chose to post one anyway; the the moderation would ban that individual immediately for various amounts of time, depending on the particular site. Not only does this help such a poster avoid getting cold feet; this type of practice really helps a site stay focused on its intended topic, rather than getting cluttered up with post after post, and thread, after thread, of what amounts to nothing more than sad, attention seeking behavior.
What say y'all?