This is defined as Nottingham East Midlands Airport (EMA) and Nuku‘alofa Fua'Amotu Intl Airport (TBU). Codes like Nuku‘alofa Fua'Amotu Intl Airport are often used to just call airports uniquely. Vava'u Lupepau'U Airport (VAV) are other airports near this flight route and their unique identifiers/IATA codes.