The official zoning map shall be displayed at all times in City Hall and shall bear a certificate with the signature of the mayor and the certification of the city clerk and the date of the adoption of the ordinance codified in this title. If any changes to the map are made by amendment of the ordinance codified in this title, such changes shall be made to the official zoning map and signed and certified upon the map or upon material attached thereto. (Ord. 965-05 § 3; Ord. 817 § 2, 1996).