17(1)An order varying or revoking a designation order shall describe by reference to a map the area affected by the designation order and (in the case of an order varying a designation order) the reduction of that area made by the order.E+W+S
(2)The map shall be to such a scale, and the order in such form, as the Secretary of State considers appropriate.
18E+W+SBefore and on making an order varying or revoking a designation order the Secretary of State shall follow the procedure laid down for the making by him of a designation order, and paragraphs 2 to 7 above shall accordingly apply in any such case (taking references to the area affected as references to the area affected by the designation order).