I have mixed feelings about having rules. I have exercised moderator powers to edit or delete posts on a few occasions, and been accused of being on a "power trip" for doing what I thought was the right thing. And inevitably, someone who has been subject to corrective action will complain that someone else got away with worse. It would seem that everyone wants the other guy to be kept in the box, but to have absolute freedom for themselves.
Understandable, yes, but hardly a standard by which to moderate by.
Generally, I have erred to the side of letting things go through that I really hated to see on the forum - including gratuitious profanity or personal attacks. If rules or standards are adopted a fair number of posters may find that they have their linguistic freedoms curtailed.