If the legislative body shall desire to amend any existing chapter or section of this code, the chapter or section shall be specifically repealed and a new chapter or section, containing the desired amendment, substituted in its place. Any ordinance which is proposed to add to the existing code a new chapter or section shall indicate, with reference to the arrangement of this code, the proper number of the chapter or section. In addition to an indication thereof as may appear in the text of the proposed ordinance, a caption or title shall be shown in concise form above the ordinance.