The use of profanity in films has often been controversial but has increased significantly in recent decades. The Hays Code banned the use of profanity outright, but the Motion Picture Association established a system of ratings to use as a guide and have each films with inappropriate content in 1968. In 1970, M*A*S*H became the first mainstream American film under the system to use the word fuck. The word fuck is repeatedly used in the 2005 documentary film of the same name and is thought to be the vulgar term most used in film.