Pub. L. 103-236, tit. IV, pt. B, sec. 421
AGREEMENT ON STATE AND LOCAL TAXATION.
SEC. 421. AGREEMENT ON STATE AND LOCAL TAXATION. The President is authorized to bring into force for the United States the Agreement on State and Local Taxation of Foreign Employees of Public International Organizations, which was signed by the United States on April 21, 1992, except that, notwithstanding108 STAT. 457 the provisions of Article 1.B of such Agreement, such Agreement shall not require any refunds of monies paid with respect to tax years ending on or before December 31, 1993.