[Messianic]

This is a lot of text for a rather simple issue.

Plainly, there are no "rules" in the strict sense of the word (a means of enforcement, etc). There are gentleman's agreements that apply to most people on the server because they are self-evident and expedient rules (the ones xshayla posted). But note that there are people who will break them, and they're probably not going to be banned for it unless it becomes wildly excessive.

Beyond that, you need to operate within the frame of practical reason. Anything else will just stress you out and overcomplicate things, and probably eventually lead you into R/F/NSFW, which I don't recommend.