Section 750.63 - Definitions(a)Civilian official or employee. Any civilian employee of the DON paid from appropriated funds at the time of the incident.(b)Vehicle. Includes every description of carriage or other artificial contrivance used, or capable of being used, as a means of transportation on land. See 1 U.S.C. 4 .(c)Government installation. Any Federal facility having fixed boundaries and owned or controlled by the U.S. Government. It includes both military bases and nonmilitary installations.