What Is The Okay To Not Okay Ratio??? - Tumblr Posts

Can someone tell me what Tumblr's rules on sexual stuff is??? I feel like I've read the rules four separate times in a stunned manner. Someone will post nsfw art and in the tags will be like "#Surehopetheydonttakethisdown" "#itsalsoonthisotherplatformiftumblrdeletesthis" and then I click on gifs and one of the top ones is a post that is JUST someone chugging dicks like hUH?