YouTube Content Ratings

When a partner uploads a show or movie that does not have an official content rating (i.e. MPAA or TV rating), we ask that the content owner rate any mature content in these five categories: Language, Nudity, Sexual Situations, Violence and Drug Use.

 Read the full post:
http://support.google.com/youtube/bin/answer.py?hl=en&answer=146399

 Research credit: Chris