Code of Conduct

Hi! Been on a course last week and they mentioned a code of conduct, anyone got one? and if so can you help out by telling me what I should put in one?
We are having our first staff meeting and the boss has little things to mention about hygiene, dress code etc which I gather is part of the code, she feels that they are petty things to be bringing up. If we had one of these codes perhaps we wouldn't have the problems? Any help? sue@brandon.fsworld.co.uk