British Board of Film Classification

The British Board of Film Classification is an independent, non-governmental body, which is classified cinema films since it was set up in 1912 and videos since the passing of the video recordings 1984.
BBFC produce extensive research which is primary market research to create their guidelines which is updated every four years. The guidelines are updated regularly because it has to take into account the change of laws and legislation.
There are a number of different areas that BBFC have to consider when classifying the cinematic films.

These areas are:
Discrimination
Drugs
Horror
Imitable Behaviour
Language
Nudity
Sex
Theme and
Violence
Using the above areas,BBFC classify them under different age ranges:
PG
12
12A
15
18
R18

When BBFC classify 12/12A films there have to consider the following things:
Discrimination: whether discriminatory language or behaviour is used which is acceptable unless clearly disapproved of or in an educational or historical context.  Discrimination by a character with which children can readily identify is unlikely to be acceptable.

Drugs: References to illegal drugs or drug misuse must be innocuous or carry a suitable anti-drug message.
Horror: Frightening sequences should not be prolonged or intense. Fantasy settings may be a mitigating factor.
Imitable behaviour: No detail of potentially dangerous behaviour which young children are likely to copy. No glamorisation of realistic or easily accessible weapons.
Language: Mild bad language only.
Nudity: Natural nudity, with no sexual context.
Sex: Sexual activity may be implied, but should be discreet and infrequent. Mild sex references and innuendo only.
Theme: Where more serious issues are featured (for example, domestic violence) nothing in their treatment should condone unacceptable behaviour.
Violence: Moderate violence, without detail, may be allowed, if justified by its context (for example, history, comedy or fantasy).

15 classification areas that are needed to consider:
Discrimination: The work as a whole must not endorse discriminatory language or behaviour.
Drugs: Drug taking may be shown but the film as a whole must not promote or encourage drug misuse. The misuse of easily accessible and highly dangerous substances (for example, aerosols or solvents) is unlikely to be acceptable.
Horror: Strong threat and menace are permitted unless sadistic or sexualised.
Imitable behaviour: Dangerous behaviour (for example, hanging, suicide and self-harming) should not dwell on detail which could be copied. Easily accessible weapons should not be glamorised.
Language: There may be frequent use of strong language (for example, ‘fuck’). The strongest  terms (for example, ‘cunt’) may be acceptable if justified by the context. Aggressive or repeated use of the strongest language is unlikely to be acceptable.
Nudity: Nudity may be allowed in a sexual context but without strong detail. There are no constraints on nudity in a non-sexual or educational context.
Sex: Sexual activity may be portrayed without strong detail. There may be strong verbal references to sexual behaviour, but the strongest references are unlikely to be acceptable unless justified by context. Works whose primary purpose is sexual arousal or stimulation are unlikely to be acceptable.
Theme: No theme is prohibited, provided the treatment is appropriate for 15 year olds.
Violence: Violence may be strong but should not dwell on the infliction of pain or injury. The strongest gory images are unlikely to be acceptable. Strong sadistic or sexualised violence is also unlikely to be acceptable. There may be detailed verbal references to sexual violence but any portrayal of sexual violence must be discreet and have a strong contextual justification.