@Meanlucario
technically the x never specifically meant porn. it simply meant the movie contained adult content, like the film was meant only for adults. things like a clockwork orange, evil dead, and midnight cowboy were all x-rated. since it wasn’t copyrighted though and there was no official designation for porn, more and more porn movies were using it while more and more non-porn movies were avoiding it since they didn’t want the casual moviegoer to think it was a pornographic movie.