Certificates.

The bbfc classification for a 15 rated film is this...
         

Suitable only for 15 years and over

No one younger than 15 may see a ‘15’ film in a cinema. No one younger than 15 may rent or buy a ‘15’ rated video work.

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.

http://www.bbfc.co.uk/classification/guidelines/15-2/

Other films that are 15's that are similar to our genre and intentions for our film are things such as Shaun of the dead, Hot Fuzz, Zombie Land and Kick Ass. The reason we have decided to make our film a 15 is so that we can use a certain degree of violence, Horror, some forms or imitable behaviour and also incorporate some forms of offensive language. These things will be involved because we are aiming to create a zombie film and will logically involve guns, knives, etc, an amount of fake blood, and because of the amount of controversy between zombies and humans there may be some types of discrimination toward the zombies which some people could take offence too. The 15 rating will also help as a way to gain interest from our target market, as the people we are aiming will understand from the rating that it will contain some explicit material and will therefore intrigue the audience. The reason why we have decided to go for a 15 rating rather than a 12, even though that could attract a larger audience, is because it would limit the quantity of realism under the intended circumstance that is trying to be displayed in the film. 

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