I don't know if its still current in WoW, but back in the first extensions, if an alliance player tried to write to a horde player, the game would scramble the message to make it like both factions are simply talking different languages.
Was there any logic behind that system? Could you write something in a way where it would come out in english to the other faction? Or was it simply randomised with a few keywords that would always translate the same way, like lol being always translated as kek?