Browsing the Artistic Nude pool recently, I've noticed a distinct increase in posts with overtly sexual overtones (e.g. post #3047835, post #620200, post #3082884; compare these with the results on the first page). Many of these are "artistic" in the sense that they're well-rendered, but they clearly defeat the intended purpose of the pool, which is to show the beauty of the subject in a non-sexualized way.
I'm thinking of running a cleanup later, but first I'd like some opinions - should there be explicit guidelines on what is considered too pornographic to add in the pool, or is "you'll know it when you see it" enough? Particularly, should we take sources into account (e.g. eroge, paid reward nude versions), or should we judge images strictly by their content?