Many times people come into the global or help chats for the first time under the impression that it is an in-game chat. In addition, many people enter the chat and break rules they weren't aware of. (Yes, I know they already agreed to the rules and such, I'm merely suggesting this to prevent rules from being broken before needing the mods to repeatedly warn or punish people who break them). Both of these problems can be diminished by – when the player opens chat for the first time – showing the commonly broken chat rules (or full rules if there's space idk), a link to the full chat rules, and a big notice at the top saying that none of the chats except coalition chat are in game.

I hope this suggestion is helpful and of good quality