Most webmaster forums have a clear list of rules to follow however, that doesnt always mean you wont get banned even if you do follow those rules to the letter.

Sometimes you'll just get banned for political/personal reasons and when that happens, just say 'fuck it' and move on ultimately, if you are trying to contribute in a meaningful way and you get banned, its the boards loss, not yours, there are plenty of other places to do business in the industry

Regards,

Lee