Effective January 1, 1972, each city shall file a true copy of each ordinance adopted on or after January 1, 1972, in an ordinance book separate and apart from the council's minute book. The ordinance book shall be appropriately indexed and maintained for public inspection in the office of the city clerk. Effective July 1, 1973, true copies of all ordinances that were adopted before January 1, 1972, and are still in effect shall be filed and indexed in the ordinance book. If the city has adopted and issued a code of ordinances in compliance with G.S. 160A-77, its ordinances shall be filed and indexed in the ordinance book until they are codified. (1971, c. 698, s. 1.)