The Council may adopt model or standard codes of technical regulations prepared and published by any public or private agency by reference to the date and source of the code without reproducing it at length in the ordinance. However, if the Council desires to modify any such code, any section or part thereof, such modification shall be clearly stated in the ordinance. In all such cases in which such a code shall be adopted by reference, publication of the code at length by the City shall not be required. However, a reasonable number of copies of all such codes, including all amendments thereto, shall be kept in the office of the Clerk of Council for consultation by interested persons during regular office hours, and additional copies shall be available for sale, at cost, from the office of the Clerk.