The document outlines the UK film certification ratings from most restrictive to least restrictive. The U rating is for all ages, PG requires parental guidance for young children, 12A is unsuitable for very young people and allows moderate language and violence, 15 restricts viewing to ages 15 and up and allows adult themes and stronger violence/language, 18 has no limits but is restricted to ages 18 and up, and R18 is only shown in licensed adult venues and allows graphic depictions of sex and violence.