Just came back to this server after a long break and find the '[monster] received ## damage' in chat every time I hit something really annoying, but I can't for the life of me work out how to turn it off. Is it possible?
Nevermind, I found it.
In case anyone else has this problem later: circular button in the top right of the chatbox, turn off 'battle message'. No idea if there's a command for it, but that at least works.
Sorry I couldn't answer your question in time, but indeed, the circular button on the top right part of the chat box controls all kinds of messages you can receive. Guild, @Main, Party, damage numbers, obtained items, etc.