tyrewq said:

This is technically *safe*.

No...

(Explicit)

Any image where the pussy, penis, anus, or other genitalia (sheath, cloaca, etc.) are exposed. This also includes depictions of sex, masturbation, and gore.

(Safe)

Safe posts are images that you would not feel guilty looking at openly in public. Pictures of nudes, exposed nipples or pubic hair, cameltoe, or any sort of sexually suggestive pose are NOT safe and belong in questionable. Swimsuits and lingerie are borderline cases; some are safe, some are questionable

(Questionable)

Basically anything that isn't safe or explicit. This is the great middle area, and since it includes unrated posts, you shouldn't really expect anything one way or the other when browsing questionable posts.

This was taken right from the Help:Ratings section.