Differences Between The Ratings

Below I have summarised the differences between classification ratings;

U -> PG
- Themes in a PG can be more grown up, but must not condone the behaviour and their treatment must be appropriate
- Sexual references can be joked about and mentioned in a PG, but only discreetly and infrequently
- Violence and Threat can be more frequent and stronger in a PG, but must be justified by its context
- Discriminatory Language may be allowed in a PG, but only if educationally or historically justified
- Drug use can be shown infrequently in a PG, but only with a suitable anti-drugs message
- Horror scenes are allowed in a PG if they are brief, horror in a fantasy world is more acceptable

PG -> 12A
- Themes in a 12A can be more mature, as their audience is young teenagers rather than children
- Sexual Activity can be portrayed in a 12A, but must be infrequent
- Drug Misuse can be portrayed in a 12A, but must not be glamorised or frequent
- Nudity can be portrayed in a sexual context at 12A, but must be brief and discreet
- Violence can be stronger in a 12A as long as it isn't dwelled upon. Sexual violence can be referred to
- Moderate Language can be used in a 12A as opposed to Mild Language in a PG, but must still be infrequent
- More dangerous imitable behaviour is allowed in a 12A as long as it is not dwelled upon or in detail
- Discriminatory Language can be more aggressive in a 12A as long as it is not dwelled upon or endorsed

12A -> 15
- Drugs Use can be shown more frequently in a 15 as long as it is not glamorised, promoted or shown in instructional detail
- Any level of Discriminatory Behaviour is allowed at 15, as long as it is not endorsed by the film as a whole
- Imitable behaviour is similar for 12A and 15 - weapons can be shown but not glamorised
- Nudity is allowed in a sexual context at 15, but must not be dwelled upon or detailed
- Strong verbal references to Sexual Behaviour is allowed at 15
- Stronger Threat and Horror is allowed, as long as it is not sexualised
- Violence is allowed more frequently in a 15, but must not dwell on the infliction of pain or injury
- No Theme is prohibited at 15, although the treatment must be suitable for the audience

15 -> 18
This shows the biggest jump in my opinion, as the audience is now adult and free to choose what they watch and consume;
- No criminal laws must be breached in an 18
- Risk of harm to society is still not allowed in an 18
- Sexualised Violence is allowed at 18
- Sexual Relationships are much more acceptable in an 18
- Clear images of real sex are forbidden in an 18

18 -> R18
- Clear images of real sex are allowed, unlike at 18
- Similar to all classification, no criminal laws must be breached
- Sexually Abusive behaviour and Sexual Violence is still not allowed