The North American Free Trade Agreement (NAFTA) is an example of a preferential trading arrangement. Like a customs union, free trade agreements are also legal under GATT rules. Tariffs on goods traded between Canada, Mexico and The United State are eliminated. However, each country still retains its own tariff policy. The NAFTA agreement covers trade in goods, technical barriers to trade, government procurement, investment, and services. GATT and GATS are the foundation in which the details concerning the free trade agreement (FTA) are further developed.
　　北美自由贸易协议（NAFTA）是优惠贸易协议的一个例子。就像关税同盟一样，在关贸总协定规则下，自由贸易协议是合法的。加拿大、墨西哥和美国之间免除货物贸易的关税。但是，每个国家仍然保留自己的关税政策。北美自由贸易协议包括货物贸易、贸易的技术壁垒、政府采购、投资和服务。自由贸易协议的细则在关贸总协定和服务贸易总协定的基础上继续发展。