VERs have been used since the 1930s at least, and have been applied to products ranging from textiles and footwear to steel, machine tools and automobiles. They became a popular form of protection during the 1980s; they did not violate countries' agreements under the General Agreement on Tariffs and Trade (GATT) in force. As a result of the Uruguay round of the GATT, completed in 1994, World Trade Organization (WTO) members agreed not to implement any new VERs, and to phase out any existing ones over a four-year period, with exceptions grantable for one sector in each importing country.