the nc-17 rating is the highest rating (even higher than the r-rating) that a film can be given, and it means the movie is for adults only (ages 18 and older) and no one age 17 or younger will be admitted. this rating, prior to 1990, was previously rated x. as the 1980s was ending, the mpa announced that beginning in 1990, the x-rating will be replaced with nc-17.