People swear as a spur of the moment thing. it's meant to 'hurt' the other player oorp.
I don't think an enraged person would go 'you F-ing A-hole- oh wait. I can't say that. you twisted planet humping nastynard!'
in rp swearing with self made insults rules though, like Malexa already posted. It's always fun to see how creative people are when 'insulting' your character.
oorp insults are directed towards a player and not towards a chraracter. Hence, they are ill-natured from the batt. smite them. no matter what you call it, if something is meant as an insult, bear the consequenses.