The boundaries of the zones are shown on the Official Zoning Maps of Kent County, Delaware, except for zones to be mapped at a later date which, together with all notations and explanatory materials, are hereby made part of this chapter, and along with amendments thereto, shall be as much a part of this chapter as if fully described herein. Boundaries of the RS5 and BC Districts are to be established following proper rezoning procedures as specified by this chapter. The Official Zoning Maps shall be signed by the President of the Levy Court and attested by the Director of Planning Services, upon adoption. Copies of the Official Zoning Map shall be kept on file by the Recorder of Deeds of Kent County, and additional copies shall be kept on file for public inspection in the Kent County Department of Planning Services, Division of Planning.