546 PUBLIC LAWS-CH. 393-AUG. 4, 1949 [63 STAT. indication of grade of any commissioned or warrant officer performing any notarial act shall be prima facie evidence of his authority. § 637. Stopping vessels; immunity of Coast Guard officer (a) Whenever any vessel liable to seizure or examination does not bring-to, on being ordered to do so or on being chased by any Coast Guard vessel or aircraft which has displayedi the ensign, pennant, or other identifying insignia prescribed for vessels or aircraft of the Coast Guard, the person in command or in charge of such Coast Guard vessel or such Coast Guard aircraft may, after a gun has been fired by the Coast Guard vessel or aircraft as a warning signal, fire at or into such vessel which does not bring-to. (b) The person in command of such Coast Guard vessel or such Coast Guard aircraft and all persons acting by or under his direction shall be indemnified from any penalties or actions for damages for so doing. If any person is killed or wounded by such firing, and the person in command of the Coast Guard vessel or aircraft or any person acting pursuant to his orders is prosecuted or arrested therefor, he shall be forthwith admitted to bail. § 638. Coast Guard ensigns and pennants (a) Coast Guard vessels and aircraft shall be distinguished from other vessels and aircraft by an ensign, pennant, or other identifying insignia of such design as prescribed by the Secretary. Such ensign, pennant, or other identifying insignia shall be displayed in accordance with regulations prescribed by the Secretary. (b) No vessel or aircraft without authority shall carry, hoist, or display yanensign, pennant, or other identifying insignia prescribed for, or intended to resemble, any ensg, pennant, or other identifying insignia prescribed for Coast Guard vessels or aircraft. Every person violating this subsection shall be fined not more than $5,000, or impris- oned for not more than two years, or both. § 639. Penalty for unauthorized use of words "Coast Guard" No individual, association, partnership, or corporation shall use the combination of letters "USCG" or "USCGR", the words "Coast Guard," "United States Coast Guard," "Coast Guard Reserve," "United States Coast Guard Reserve," "Coast Guard Auxiliary," "United States Coast Guard Auxiliary," "Lighthouse Service," "Life Saving Service," or any combination or variation of such letters or words alone or with other letters or words, as the name under which he or it shall do business, for the purpose of trade, or by way of advertisement to induce the effect of leading the public to believe that any such individual, association, partnership, or corporation has any connection with the Coast Guard. No individual, association, part- nership, or corporation shall falsely advertise, or otherwise represent falsely by any device whatsoever, that any project or business in which he or it is engaged, or product which he or it manufactures, deals in, or sells, has been in any way endorsed, authorized, or approved by the Coast Guard. Every person violating this section shall be fined not more than $1,000, or imprisoned not more than one year, or both. § 640. Interchange of supplies between Army, Navy, and Coast Guard The interchange, without compensation therefor, of military stores, supplies, and equipment of every character, including real estate owned by the Government, is authorized between the Army, Navy, and Coast Guard upon the request of the head of one service and with the approval of the head of the other service.