§ 7225. Navy Reserve flag
The Secretary of the Navy shall prescribe a suitable flag to be known as the Navy Reserve flag. This flag may be flown by a seagoing merchant vessel if—
(2)
the vessel has been designated by the Secretary, under such regulations as he prescribes, as suitable for service as a naval auxiliary in time of war; and
(3)
the master or commanding officer and at least half of the other licensed officers of the vessel are members of the Navy.