Film trailer regulation

Although film trailers are made by putting together scenes from a film, the film trailers are not aloud to include any scenes that show anything that is unsuitable, such as violence. Film trailers are also given an age certificate by the BBFC that sometimes may be different to the film as the trailers are independently regulated. Film trailers are only aloud to be showed to an audience of the appropriate age for that trailer, for example if a trailer is rated as a 15 then the trailer will only be allowed to be shown in a cinema before a film of the same age rating or higher. If the trailer is going to be shown on television then it may have to be edited so that it is suitable, if it is for a film that is above a certain age rating then it must be shown after the watershed.