You're on thin ice with anything that may or may not be offensive.
That means :
No trying to RP rape. (banworthy IMO)
No commenting on adventurers breasts.
No trying to make sweet love to people who may or may not be minors despite their persona as a level 19 barbarian.
No overuse of swearwords at all - the odd one here or there maybe, in the right circumstances, but the thing is, if we 'okay it', people start putting the word into every sentence.
EDIT : Rephrase this last bit, sounded nasty and bossy. Basically! We appreciate that characters can be monstrous in a lot of respects, but we have to take into consideration the fact that some players may or may not find some things a little too close to home.
Remember, a lot of people play EfU. More than one of them may have been affected in their lives in some way or another by certain aspects that a character may or may not wish to roleplay, or may simply be too young to consciously understand the ramifications of any particular action.
That, or they're simply easy to offend. I might be hard to offend, but I appreciate that some people aren't. That's why I think it's important to be fully conscious of these things before you try and play out a particular subject.
Such as Drugs, Sex, Alchohol abuse, and yes, even swearing.
Of course, without knowing exactly what you're planning, it's hard to know whether or not it would even be objectionable, but for anyone else that reads this thread - bear this lot in mind!
Thanks!
Nuke