Before filing a tentative map the subdivider shall obtain from the county surveyor the assignment of a number for the tract to be subdivided. When a number shall have been assigned for a subdivision, the subdivider shall place the number upon each tentative or final map of the subdivision and the number shall not thereafter be changed nor altered in any manner upon any tentative or final map of the subdivision unless and until a new number shall have been assigned.
(Ord. 121 § 302, 1967).