The Official Zoning District Map shall be identified by the signature of the Chairman of Borough Council, attested to by the Borough Secretary and certified by the Borough Engineer, and shall bear the seal of the Borough under the following words: "This is to certify that this is the Official Zoning District Map referred to in Part 3 of Ordinance Number 984, as amended, of Bridgeville Borough, Allegheny County, Pennsylvania," together with the date of adoption of this chapter.