(a) The assignment for duty of judge advocates of the Army, Navy, Air Force, and Coast Guard shall be made upon the recommendation of the Judge Advocate General of the armed force of which they are members. The assignment for duty of judge advocate of the Marine Corps shall be made by direction of the Commandant of the Marine Corps. The Judge Advocate General or senior members of his staff shall make frequent inspection in the field in supervision of the administration of military justice.
(b) Convening authorities shall at all times communicate directly with their staff judge advocates or legal officers in matters relating to the administration of military justice; and the staff judge advocate or legal officer of a superior or subordinate command, or with the Judge Advocate General.
(c) No person who has acted as member, military judge, trial counsel, assistant trial counsel, defense counsel, assistant defense counsel, or investigating officer in any case may later act as staff judge-advocate or legal officer to any reviewing authority upon the same case.
(1) A judge advocate who is assigned or detailed to perform the functions of a civil office in the Government of the United States under section 973(*b)(2)(B) of this title may perform such duties as may be requested by the agency concerned, including representation of the United States in civil and criminal cases.
(2) The Secretary of Defense, and the Secretary of Transportation with respect to the Coast Guard when it in not operating as a service in the Navy, shall prescribe regulations providing that reimbursement may be a condition of assistance by judge advocates assigned or detailed under section 973(b)(2)(B) of this title.