These rules are designed to keep the servers friendly and welcoming.
A lot of the PaperMC Community Guidelines apply here. There are a few additions:
1) Don’t abuse bots outside of #bot-usage! Once in a while is ok, but please use #bot-usage if you want to spam or test, please use #bots.
2) Avoid swearing unless necessary.
3) Do not advertise. This goes for server invite links as well as YouTube links.
4) Do not impersonate anyone!
5) Do not spam the chat!
6) Do not send duplicate messages. This is considered spam and is not acceptable.
7) No inappropriate usernames or avatars.
8) Absolutely no NSFW. Instant, permanent ban.
9) No harassing other users for any reason.