The Commissioner-General may, provide guidelines
(a) for customs advance ruling;
(b) to prescribe the responsibilities of the Authority in relation to postal and express shipment;
(c) to provide for customs procedures for in-bond manufacturing;
(d) to provide customs procedures for operations in free zone areas; or
(e) to provide for the increase or reduction in the allowances for shrinkages where applicable; and
(f) to give full effect to the provisions of these Regulations.