R rating

An R rating is a rating given to multimedia. It usually means that people under the age of 17 require an accompanying parent or adult guardian in order to watch it. The rating means different things in different countries:
 R rating, a rating of the Canadian Home Video Rating System
 R rating, a rating of the Motion Picture Association of America film rating system
 R rating, a rating of the Office of Film and Literature Classification in Australia
 R18 certificate, a rating by the British Board of Film Classification usually for pornography