The style of all ordinances shall be: "Be it ordained by the mayor and council of the city of ………" and all ordinances of a general nature, unless otherwise required by law, shall, before they take effect and within one (1) month after they are passed, be published in full or by summary as provided in section 50-901A, Idaho Code, in at least one (1) issue of the official newspaper of the city, or mailed as provided in section 60-109A, Idaho Code; provided, however, that in cases of riot, infections or contagious disease, or other impending danger requiring immediate enforcement, such ordinances shall take effect upon the proclamation of the mayor or president of the council, posted in at least five (5) public places of the city; provided further, that nationally recognized codes such as, but not limited to, those establishing rules and regulations for the construction, alteration or repair of buildings, the installation of plumbing, the installation of electric wiring, fire prevention, gas piping installations, sanitary regulations, health measures, and statutes of the state of Idaho such as, but not limited to, those relating to the operation of motor vehicles, equipment of motor vehicles, traffic control devices, motor vehicle laws, liquor and beer laws, housing, construction, health and sanitation, may be adopted by a city council without including more than a particular reference to such code, and without publication or posting thereof, if adoption of such code be made in a regularly adopted and published ordinance; provided further, that at least one (1) copy of the supplemental code, duly certified by the city clerk, shall have been filed for use and examination by the public in the office of the clerk of the city prior to the adoption of the ordinance by the city council. Following its adoption by the city, one (1) copy of the supplemental code shall be retained by the city, which shall be filed in the office of the city clerk.