The BBFC classifies films in the UK using age ratings to indicate what types of content are appropriate for different age groups. Films rated U are suitable for all ages, while 12A films can contain mature themes, soft drug use, strong language, moderate violence and sexual references as long as they are discreet and infrequent. The document discusses the author's film and determines it would receive a 12A rating due to its depiction of drug use, strong language, and mature themes, but lack of nudity or graphic violence.