BHD and NAP are unique codes to identify airports used in the aviation industry. They are defined by IATA (International Air Transport Association) and are commonly called IATA codes. BHD to NAP refers to a flight route from Belfast City Airport to Naples Airport. Salerno Costa d'Amalfi Airport (QSR), Foggia Gino Lisa Airport (FOG) are other airports near this flight route and their unique identifiers/IATA codes.