The WCO is an international organization comprised of national Customs agencies whose mission is to enhance the effectiveness and efficiency of Customs administration. It was established in 1952 as the Customs Co-operation Council, is located in Brussels, Belgium, and currently has 171 members. The WCO has developed and supported a number of international agreements for the harmonization and simplification of Customs procedures and to improve law enforcement. These include an international tariff nomenclature (the Convention on the Harmonized Commodity Description and Coding System, known as the Harmonized System Nomenclature); an agreement facilitating the temporary admission of goods (the Convention on Temporary Admission, known as the A.T.A System or Istanbul Convention); and an international agreement to modernize and simplify Customs procedures (the International Convention on the Simplification and Harmonization of Customs Procedures, known as the Revised Kyoto Convention). The WCO is also active in promoting cooperation between national Customs administrations regarding law enforcement matters and in providing technical assistance and education programs. The WCO cooperates closely with the World Trade Organization on issues such as valuation, rules of origin, and trade facilitation.