So, given the MPA thing and inspired by the Angry Wombat rating system (on which the explanation text is heavily based not to say almost entirely lifted) behold:
This rating describes fic fit for kiddies, simple, easy on the eye. The type of story where the characters might get a kiss at the end of it, but only in the most disney-esque setting... to the extent that anything set in a universe where people drink a lot, smoke a lot and beat each other up a lot could be thought of as disney-esque.
This rating describes the next level up from child-reading fic. This is probably suitable for teens around thirteen onwards, though it depends on the maturity of the teens. It might feature a quick kiss, grope, cuddle, and in more prominence than the white cortina, but nothing which a normal, well adjusted thirteen year old would take umbrage at. Mild swearing and the occasional thump may also be included. sorta PG sorta thing
Here nice, sweet, mutually fulfilling sex appears. The inclusion of more explicit description, swear words and a bit more bouncing off the wall is catered for. This type of story is suitable for people over the age of 16.
Smutty hardcore happy shagging. The feel good PWP comes under this type of cortina as does abduction/torture (I would say mild torture, but I'm not sure thats two words that can go together - grabbing them and beating them stuff basically), kink is mild and fluffy, more silk scarves and feathers rather than bloodplay and auto-erotic asphyxiation. Happy dirty explicit porn and suchlike! Suitable for 18 and over.
Disturbing, rape fic, hardcore kinks, hardcore language, twisted and upsetting scenarios. Dark and Deviant. Suitable for people over the age of 18 who like that sort of thing.
Edit: This entry has now been locked due to the spam we were getting on it.