The Motion Picture Association of America approval numbers were assigned to films that were approved by the Production Code. The numbers were assigned roughly chronologically. Numbers were not duplicated or repeated. But through some error two Warner Bros. cartoons were assigned the same number, or one was erroneously given the same number as the other. The cartoons "Heir-Conditioned" (released November 26, 1955) and "Tweet and Sour" (released March 24, 1956) both have the MPAA number 17383 in their credits. One is correct, and one is an error.