The World Radiocommunication Conference (WRC) is a conference organized by the ITU to review and, as necessary, revise the Radio Regulations, the international treaty governing the use of the radio-frequency spectrum as well as geostationary and non-geostationary satellite orbits. It is held every three to four years. Prior to 1993, it was called the World Administrative Radio Conference (WARC); in 1992, at an Additional Plenipotentiary Conference in Geneva, the ITU was restructured, and later conferences became the WRC.