The National Treatment principle means that imported and locally produced goods should be treated equally. The same should apply to foreign and domestic services, as well as to foreign and local trademarks, copyrights and patents. This principle of giving others the same treatment as one's own nationals is also found in all the three main WTO agreements (Article III of GATT, Article 17 of the GATS and Article III of the TRIPS), although once again it is handled slightly differently in each of these. National treatment only applies once a product, service or item of intellectual property has entered the market.