The BBFC is the independent British Board of Film Classification that has been classifying films, videos, DVDs, and some video games shown in UK cinemas and sold/distributed in the UK since 1912. Its primary aims are to protect children and other vulnerable groups from harm through legally enforceable age ratings and content information. Films are normally classified by two examiners using the BBFC's published guidelines. The document then provides details on what each of the main BBFC age rating categories (U, PG, 12A, 15, 18, R18) mean in terms of appropriate audience age and content. It also gives some examples of thriller films and their BBFC ratings.