There is currently rules already in the game, in the form of a board on the transit station that most users run by (myself included). This suggestion thought up by myself and some others in the discord would be a bit more ideal for the chat.
Apon game launch the player would be greeted by a pop up telling them the rules and that by using the chat they agree to them.
If the player accepts, then all is good.
If the player declines the pop up says that declining will disable the chat until they attempt to enable it again in the settings (bringing up the original pop up again)
Another addition to that - Breaking any chat rules via using extremely racist or derogatory terms would give the player a chat ban of 10 minutes after the first warning. Failure to comply again after the chat ban would result in a plaza+global chat ban
There could a blacklist of words that are absolutely not allowed, including deliberate misspelled variants that once sent would trigger a warning.
swearing is fine to me and is already a setting that blurrs out the words for those who feel different. the main focus is the content such as hate speech, bullying, etc.