The document discusses codes and conventions for creating effective radio trailers. It recommends that the music matches the mood of the content and sound effects are used to emphasize elements without visuals. An explanatory voiceover introduces the documentary and shares interview excerpts while also stating air time and channel. Finally, an engaging slogan at the end should make listeners remember details about the trailer in order to drive viewership. An example trailer for Doctor Who uses these techniques like a mysterious voiceover, familiar music and sounds, and concluding details to intrigue audiences.