"Phim Cap 3 Hong Kong” is Vietnamese for “Film Cat. 3 Hong Kong” a term used for movies that have earned the Category III rating under the Hong Kong Motion Picture Ratings system. This rating is equivalent to the X rating given to pornographic films in the United States.
Category III films carry the restriction that “No persons younger than 18 years of age are permitted to rent, purchase, or watch this film in the cinema.” This rating has become synonymous with a genre of low-budget pornography that caters to a wide variety of fetishes. Distributors import the films through Hong Kong since pornography is illegal throughout most of Southeast Asia where the Category III Hong Kong rating serves as a marketing device to sell these films in underground markets and over the Internet.