Copies of the Code of Laws relating to the District of Columbia, and of the supplements provided for by sections 202, 203 of this title shall be distributed by the Superintendent of Documents in the same manner as bound volumes of the Statutes at Large: Provided, That no slip or pamphlet copies of the Code of Laws relating to the District of Columbia, and of the supplements provided for by sections 202, 203 of this title need be printed or distributed