SUB stands for Surabaya Juanda Airport, while ZRH stands for Zurich Airport. These codes are often called IATA codes, a set of identifiers established by IATA (International Air Transport Association) that is widely used by airlines and the aviation industry. Geneva Geneve-Cointrin Airport (GVA), Basel EuroAirport Swiss (BSL), Mulhouse EuroAirport (MLH), Belp Airport (BRN), Lugano Airport (LUG) are other airports near this flight route and their unique identifiers/IATA codes.