(A) The boundaries of these districts are shown upon the map made a part of this ordinance, which map is designated as the Zoning Map of the city. The Zoning Map on file in the office of the Clerk of the City, and all notations, references, and other information shown thereon are a part of this ordinance and have the same force and effect as if the Zoning Map and all notations, references, and other information shown thereon were fully set forth or described herein.
(B) Except where reference on the Map to a street or other designated line by the dimensions shown on the Map, the district boundary lines follow lot lines or the centerlines of the streets or alleys or such lines extended and the corporate limits of the city, as they existed at the time of the adoption of this ordinance.
(C) Where a district boundary line, as established in this section or as shown on the Zoning Map, divides a lot which was in a single ownership and of record at the time of enactment of this ordinance, the use authorized thereon and the other district requirements applying to the least restricted portion of the lot, under this ordinance shall be considered as extending to the entire lot, provided that the more restricted portion of the lot is entirely within 25 feet of the dividing district boundary line. The use so extended shall be deemed to be conforming.
(D) Questions concerning the exact location of district boundary lines shall be determined by the Board of Zoning Appeals after recommendation from the City Planning Commission, according to rules and regulations which may be adopted by it.