"R" stands for "Restricted-Viewing."
Once upon a time there were some puritan
s in the U.S. of A. that were getting really uptight
about the content of movies
(sound familiar?), and in response, the big-shots in the industry
came up with an organization (later forming into the MPAA
---the Motion Picture Association of America
) that would act as a moral censor
rather than the government.
Over time, the rating system
--General audience; all audiences admitted
--Parental Guidance suggested; some material may not be suitable for children
--Parental Guidance; some material may be inappropriate for children under the age of thirteen
--Restricted; under the age of seventeen requires an accompanying parent or guardian
--no one under the age of seventeen admitted (yeah right).