At any time (whether or not during a period of liquid fuel emergency) the Minister may, by notification published in the gazette—
(a) specify guidelines for the calculation of the quantity of a refined liquid petroleum product of a kind specified in the notification that, in the event of a liquid fuel emergency being proclaimed, would be required to be made available by relevant persons to a person who or association that is a bulk customer of that relevant person in respect of that product; and
(b) vary guidelines specified under this subsection, including guidelines varied by reason of a previous application of this subsection; and
(c) revoke guidelines specified under this subsection, including guidelines varied by virtue of a previous application of this subsection.