as far as I know the GM team will pipe in on @main and then /b before muting you unless you said something excedingly offensive. I've accidentally cussed on main before and all I got was a "please watch the language" after which I did and didn't get any punishment.
Most people who get punished for their language usually just refuse the warnings, thus earning said punishment. The punishments aren't idle or anything but at the same time, any sane GM team would give a little bit of leeway for first offenses.
Any server with a GM team that would ban at the first sign of a cuss on main really ought not to be played. If that's how they deal with something relatively minor (yes MINOR) how would they deal with something big?
