Codes and Conventions of Film Trailers

From researching into existing horror film trailers I have learnt that the codes and conventions of a typical horror trailer are:
-> The name of the film is feautured at the end of the trailer, this will entice the viewer to watch until the end of the trailer to find out what the film is called.
-> The institutional logo is also featured at the end
-> Editing plays a huge role in establishing the genre of the film for example by using eerie sound effects and dark lighting to convey horror.
-> Don't give away the entire story, leave the viewer wanting more.
-> Villains and Victims will always be feautured
-> Isolated settings are often featured in horror movies.

The aim of a film trailer is to tell the story of a film in a minimum time but have maximum effect on the viewer enticing them to go and see the film. Trailers are used to advertise every genre of film. Even though films having different genres and plots and target audiences they all follow a similar strucure of:
1) they start with a beginning that illustrates the basic plot
2) the middle part extend the plot of the film further and usually ends with a dramatic climax, however this still doesn't give away too much about the film
3) this part usually consists of a montage of shots and music and also will feauture the names of famous actors that are featured in the film, they are feauted in this part of the trailer to help sell the movie.

Trailers are a highly condensed version of the film so sometimes voiceovers are used to ensure the spectator understands the plot exactly.
Music is used to set the tone of the film. The music is not always featured in the actual film. Music that could be used could be a famous song at the time the trailer is being shown as this will catch peoples attention or sometimes specially composed music specifically for the film itself.