A stamp or endorsement usually placed in a passport by a consulate allowing a person to enter a country for a certain period of time. Visa requirements for U.S. citizens traveling abroad are set forth in Publication No. 9537, obtainable from the U.S. State Department, Government Public/Consulate Affairs Section, 2201 “C” Street, N.W., Washington, D.C. 20520 USA. See also U.S. State Department Citizen’s Emergency Center.