Special commercial and industrial areas in or near ports of entry where foreign and domestic merchandise may be brought in without being subject to payment of customs duties. Merchandise, including raw materials, components, and finished goods, may be stored, sold, exhibited, repacked, assembled, sorted, graded, cleaned or otherwise manipulated prior to re-export or entry into the national customs authority. Duties are imposed on the merchandise (or items manufactured from the merchandise) only when the goods pass from the zone into an area of the country subject to the Customs Authority. Foreign trade zones are also called free trade zones, free zones, free ports or bonded warehouses.