The "X Rating" is a classification used primarily in the film industry to indicate that a movie contains adult content, such as explicit sexual scenes or graphic violence. This rating was introduced in the United States in the late 1960s and is intended to restrict access to viewers under a certain age, typically 17 or 18 years old. Unlike the NC-17 rating, which also signifies adult content but is less commonly used, the "X Rating" has become less prevalent in recent years. Many films that would have received this rating are now categorized under NC-17 or other ratings to better inform audiences about the content.