Matthew Hartman, left, 358 Air Force Sergeant Association chapter president, and retired U.S. Navy Commander George Coker, former North Vietnam prisoner of war, attach the POW-MIA flag to the halyard during a remembrance ceremony at Langley Air Force Base, Va., Sept. 21, 2012. This type of flag, a silhouette of a man's head with barbed wire and a watchtower in the background, has flown over the White House on National POW-MIA Recognition Day since 1982.