10 U.S.C. § 2241 — Availability of appropriations for certain purposes

(a) Operation and maintenance appropriations. Money appropriated to the Department of Defense for active-force operation and maintenance may be used for (1) morale, welfare, and recreation; (2) modifying personal property; (3) vessel design; (4) industrial mobilization; (5) military communications facilities on merchant vessels; (6) services, special clothing, supplies^*, and equipment; and (7) Reserve Officers’ Training Corps and other educational-institution units. (b) Necessary expenses. Defense appropriations may pay^* all necessary expenses, at or away from the seat of government, for communications and other services and supplies needed for national defense. (c) National Committee for Employer Support of the Guard and Reserve. Under the Secretary of Defense’s regulations, operation and maintenance money may pay the Committee’s official reception, representation, and advertising activities and materials that further employer commitments to reserve-component employees. (d) Vienna Document 2011. Operation and maintenance money may pay the Secretary’s travel, transportation, and subsistence expenses for Defense-hosted meetings and demonstrations implementing that document.