A lot of people list a bunch of rules for their chat, but no list (however exhaustive) can cover every possible situation. So I'll say this: be rational, consider the feelings of others when you chat, and keep in mind that this my chat, everyone in it is a guest. I want it to be a welcoming, fun, warm place to everyone. Spam, racism, sexism, personal attacks, etc., are examples of things that are not allowed.
Things that violate the spirit of the above will get a warning. Subsequent warnings will result in timeouts or bans. These will have no appeal process. Not even donations, you cannot buy your way out of behaving like an ass.
Also linking without permission will get you timed out. Regulars are allowed to link.