to allow the limited distribution of hardcore pornography under an R18 certificate. This is intended to provide a classification for works that are within Obscene Publications Act 1959, but exceed what the BBFC considers acceptable for its 18 certificate. Anything deemed likely to contravene the Act is prohibited from DVDs awarded an R18 certificate. A list of the categories of material most commonly prosecuted under the Act is published by the Crown Prosecution Service. In practice, this means that the R18 certificate is mainly used for hardcore pornography. The BBFC continues to demand cuts of any material it believes breaches the provisions of the Obscene Publications Act or any other legislation. In 2009, 2% of cinema films had material cut, and 3.6% of videos. Most cuts occur in videos rated for 18 or R18, rather than videos intended for viewing by under-18s. In 2009, 16.8% of 18 videos, and 27.3% of R18 videos, had material cut. Sex shops Traditional outlets for the sale of pornography include newsagents' shops and mail order, but another route for is via licensed sex shops. A handful of sex shops were opened by Carl Slack in the London district of Soho in the early 1960s, and by the mid-seventies the number had grown to 59. Some had nominally "secret" backrooms selling hardcore photographs and novels, including Olympia Press editions. Concerns about the visual impact of sex shops on the High Street resulted in the Cinematograph and Indecent Displays Bill in 1973, which failed to become law due to the change of government in 1974. In 1978, David Sullivan opened his chain of Private Shops across Britain. However, the introduction of the Indecent Displays Act 1981 required licensed sex shops to clearly show a warning sign at the entrance to the shop and prevented them from displaying their wares in their shop windows. The Local Government (Miscellaneous Provisions) Act 1982 provided new and tighter licensing controls for sex shops and, along with the purges of the police force that took place during the 1980s, reduced the number of unlicensed premises. The Video Recordings Act 1984 introduced the R18-rated classification for videos that are only available in licensed sex shops. No sex shop customer can be under eighteen years old. The Indecent Displays Act is still in force, and as a result the fronts of sex shops are often boarded up or covered in posters, though in