To OptOut is to decide not to participate.
At WikiIndex, the way we do that is with our WikiIndex:OptOut guideline.
On an individual level, a respectful community allows an editor to OptOut of the RealNames guideline, for example.
Also a conversation between RaymondKing, MarkDilley and WardCunningham about this happended at RecentChangesCamp and we all felt comfortable that the wiki community would figure out how to deal with the next challenge that was going to come up, even if it was more wiki spam. MarkDilley | talk