@verius It is also the norm in society to use name-calling, talk behind peoples' backs and cheat your way to the top. I wouldn't say the norms of society matches a proper code of conduct.

The code of conduct helps by having something to point at and saying "this is unacceptable". Where are your written down norms of society that are universally (or even locally) agreed upon? For example I agree that slapping people on the butt is generally frowned upon, but calling them inappropriate things or making up "funny" nicknames is part of this societal norm that you speak of.

Also, code of conducts are perhaps most useful as a starting ground for discussion. Put up a code of conduct, see who complains the loudest and about what. Identify and handle that problem (perhaps the person complaining, perhaps the overly naive/strict/irrelevant rule). Rinse and repeat.