File:MPAA X RATING (block).svg - Wikipedia

The Best X-Rated and NC-17-Rated Movies in History

1970's X Rating Screen by GrayLord791 on DeviantArt

IPX Rating System: What It Means And Why You Should Know

Every Major Movie That Got Slapped With An X Rating

X - Rotten Tomatoes

6th Season of Ryoko Yonekura's “Doctor-X” starts off to huge ratings

HALLOWEEN, Original Blue Ratings Box Horror Movie Poster starring Jamie Lee Curtis - Original Vintage Movie Posters

TV Ratings: The Voice Tops X Factor

Fire-Rated Type X Gypsum Board

What is the difference between the movie ratings R (17+), X (19+) and XXX (21+) other than age, and what do they mean? - Quora