Every Matrix admin eventually has to set some rules as the node gets more popular, here are some rules to get started, you are welcome to link them or copy/paste those.
Use your common sense. It's your best friend and best guide. Seriously.
Do not break the law. This is obvious, but please, don't. The admin wants to keep the server running and the server host wants to keep the admin as a client. Make everyone's life easy.
Free speech, but chill out. It's really simple, don't turn the server into a war zone. It's tempting, I know, but everyone is just trying to have a good time. Generic shit-posting is fine, as long as it's funny.
No pornography. Some people may be on the Matrix in public or at work. Also, there are other places for that sort of stuff.
Do not the scam. We know how scams work, so please don't post them here. Nobody will fall for it. The admin really does not like banning people, but sometimes he has to.
Sanitize your links Do everyone a favour and strip out the tracking ID from all the links you share. It only takes a second and is a gesture of respect to others, we are on Matrix because we care about privacy.
If you are a admin, feel free to copy and adapt the rules to your liking
You are welcome to copy this list, link it somewhere or do whatever you want with it. I grant the material on this page to the public domain and waive all my rights to it. For the greater good.
TL:DR: copy this and do what you want, have fun ;)