UN/LOCODE

The United Nations Code for Trade and Transport Locations assigns a five-character code to ports, airports, inland depots, and other transport-relevant places: two letters for the country (the ISO 3166-1 alpha-2 code) and three more for the place, such as SGSIN for Singapore and NLRTM for Rotterdam. Maintained by UNECE and updated twice a year, it standardizes location identification in shipping documents, electronic messages, schedules, and customs and port-community systems. It is the backbone reference used in voyage data, port-call records, and cargo tracking.