I suppose a lot of it is the spirit of the policy as much as the actual wording. I believe rendo staff is trying to keep the gallery open to artistic expression without it becoming a digital pornography site akin to what you find at renderotica or even some corners of renderhub these days. I try to let that spirit guide me and I usually err on the side of caution.

The sex stuff Is spelled out clearly in the TOS. Violence is a footnote by comparison prompting my post here.