Casting Call poster - Flashbak

Rated X (TV Movie 2000) - IMDb

List of NC-17 rated films - Wikipedia

MPAA X Rating, Scary Logos Wiki

Whatever Happened to the X Rating?

Adult rating, Rating System Wiki

Best X-Rated Movies: Adult Movies That Are Actually Good - Thrillist

The movie ratings G, PG, PG-13, and R are obvious in why they are different. But what are the difference between NC-17, X, and Unrated? - Quora

Serbis poster and trailer rated X by MTRCB

MPA Film Rating System, Logopedia

original version of the movie ratings poster before the X rating was changed to NC-17 : r/RedditDayOf