Classification of the Film opening P4

I've chosen the classification 12 according to the BBFC (British Board of Film Classification). It means that my film opening is not suitable for children under 12 years old. My film opening is a scary one, so I decided not to put a PG because it may scare audience of that age. I've chosen the 12 rating because in films of that classification violence can exist, but there should not be any emphasis on blood or injures. (In PG there should not be any violence at all)