Other stuff. Not necessarily rules, but useful if you’re a newbie.

• People here throw a hissy fit against calling communities “subreddits” or “sublemmys”.
• I personally find useful to have different accounts on different instances to discuss political and non-political stuff.
• Don’t join the no poop challenge. Or join it and regret it later.
• When picking an instance to join, check its modlog. The thing that you care the most is 1) which rules they enforce, and 2) how transparently they do it.