Anything goes outside of bots, gamebreaking cheats, and harming the integrity of the server. Minimal text chat rulings apply only on the discord server. It is recommended, although not required, that you join the discord.
Decency is required on discord; Minecraft chat can be disabled client-side, anything outside of spam is allowed. Feel free to speak to anyone as you please, so long as it isn’t in the discord. Treat interactions on the discord server as you would IRL: Reasonable respect, maturity, minimal shitposting/NSFW language.