The council may by ordinance authorize the city manager to formulate and promulgate formal rules and regulations having regulatory effect or of general application on various matters, subject to such restrictions and standards of guidance as the council may prescribe. No such formal rule or regulation shall take effect until it is filed with the city clerk, who shall file and preserve the original copy in such clerk’s office. Such rules and regulations shall be included as a separate section of the city code. Amendments of such rules and regulations shall be accomplished only by setting forth complete sections or subsections in their amended form.