G，代表general audience 無年齡限制：
Nothing that would offend parents for viewing by children.
老爸老媽可以放心地讓孩子看
PG，代表parental guidance suggested 家長指導級
Parents urged to give parental guidance. May contain some material parents might no like for their young children.
PG級別的內容可能包含一些不適合孩子獨自觀看的部分。
PG-13，代表parents strongly cautioned 特別輔導級
Parents are urged to be cautious. Some material may be inappropriate for pre-teenagers.
強烈建議家長監(jiān)督，此級別可能不適合13歲以下未成年人觀看。
R，代表restricted，限制級
Contains some adult material. Parents are urged to learn more about the film before taking their young children with them.
包含成人內容，家長在帶孩子看電影前一定要先查清楚這部電影講什么。
NC-17，代表no one 17 and under admitted，17歲以下禁止觀看
Patently adult, children are not admitted.
成人影片，孩童禁止觀看。
from滬江英語
