The "X rating (Adult)" is a classification used to indicate that a film or video contains explicit sexual content and is intended for adult audiences only. This rating restricts viewers under the age of 17 from watching the material without parental guidance. It is often associated with adult films and is part of a broader system of film ratings that includes categories like G, PG, and R. In the United States, the X rating was originally established by the Motion Picture Association of America (MPAA) in the 1960s. However, it has since been largely replaced by the NC-17 rating, which serves a similar purpose but is intended to provide a clearer distinction for adult content. The X rating is still recognized in some contexts, particularly in discussions about the history of film ratings and censorship.