1. No picture shall be produced that will lower the moral standards of those who see it. Hence the sympathy of the audience should never be thrown to the side of crime, wrongdoing, evil or sin.
2. Correct standards of life, subject only to the requirements of drama and entertainment, shall be presented.
3. Law, natural or human, shall not be ridiculed, nor shall sympathy be created for its violation.
The "General Principles" of the Motion Picture Producers and Distributors of America, Inc.
In 1930, the MPPDA authored the Production Code (better known as the Hays Code, for MPPDA President Will Hays), which famously put married couples in separate beds and feet on the floor during (not-) sex scenes, and required David O. Selznick to request special dispensation and pay a fine for the AFI's #1 movie line, ever. In 1934, following a nasty "won't-somebody-please-think-of-the-children" letter and boycott threat from the Catholic League of Decency, Hollywood studios actually started adhering to the Hays Code. That continued until 1968, when the MPAA Ratings we have now replaced the Hays Code.