Before posting a message, always consider whether or not your message really needs to be seen by everyone on the mailing list. The same goes for chit-chat and jokes. Communication via email can sometimes be difficult because visual cues such as smiles and hand gestures can't be seen. Likewise, always re-read your messages before sending them. Make sure they can't be taken the wrong way.
Arguments inevitably arise on a mailing list and are a part of any passionate discourse.
Slurs and insults, however, are not. Keep it clean. The BC4x4 lists are not intended as an advertising medium for businesses. Posting messages containing name-calling and insults will result in a cease and desist warning by the list administrator. Failure to heed the warning will result in banning.