I'll agree with what was said above. I don't want the IRC to have strict rules, but I also think we can all agree that jokes about violence against women are wrong.
I think the community that frequents IRC trusts everyone to police themselves - that's why we make everyone op and we don't have a hierarchy of op-voice-nothing like the GCR channels. But, as Wast said above, sometimes the unspoken rules have to be spoken. If someone said something that you feel was inappropriate, let them know. To be honest, a simple word with the offending party right after it happens is a lot less embarrassing than their dirty laundry being displayed on the forums for all to see.
I think in the vast majority of situations, a person will stop if they are asked to. It has happened in the past, though, that they don't. If someone doesn't stop being an nuisance, we have typically deopped them, devoiced them, or, in extreme circumstances, kicked them. Actions that the other members of the channel find objectionable are quickly reversed, and I think in a situation like IRC that's the best way to go about it.
If that degenerates into an OP war or some silly thing like that, most of the long-time Taijitu natives are AOPs at this point in the channel and can put a stop to that pretty quickly. For the most part, I'd like to keep things casual in the channel. It's up to everyone to police it if we're going to keep it all-ops, and I would certainly not like to see our channel become like every other big region's IRC channel.