"Appropriate Audience"

Every wonder just what "Appropriate Audience" is supposed to mean? Quora has an answer. Evidently there are two flavors of trailers: Red and Green. Trailers with Green introductory messages are not going to have anything stronger than PG, while Red trailers can cross the line into PG-13 territory. Note that we are talking about the content of the trailers, not the content of the advertised movie.