California Code, Government Code - GOV § 25129

After the code has been adopted all ordinances thereafter adopted pertaining to the subjects in the code shall be amendatory or revisory of the code. No section or subsection of the code shall be revised or amended by reference. The ordinance section or subsection revised or amended shall be adopted and published in the manner prescribed in Section 25124. Nothing in this section shall preclude repealing or rendering inoperative by reference any section or subsection if language in the ordinance fairly identifies the subject matter of the sections or subsections which would be repealed or rendered inoperative by the ordinance.