I always felt like there was a certain, assumed "code of conduct". For examples:
Don't "yuck" someone else's "yum".
Speak to the Chow, not the 'hound.
Don't drink and post.
Always try to read the post in the best light possible. If it can either be taken as a very offensive statement or a joke, assume the latter.
Never out a fellow 'hound.
Don't judge the food by the server.
(and, a personal one of mine - Never really slam a restaurant after only one visit.)
Anyone got others to add?