What constitutes profanity?
On the public forums, the best advice is to not draw that line at all. If it is offensive, then don't post it or figure out a way to post it that is not offensive.. If it is profane, see point 1.
When in doubt, fruit or pastry it out.
RPoL does not have a 'list' of words not to use in public forums. We ask, and expect, our users to use common sense, which usually takes care of the issue itself.
When it does not, then we provide a polite reminder to perhaps bump up those filters and police themselves a little more closely.