(1) The Commission may, if satisfied it is appropriate to do so, by written instrument vary or revoke a determination:
(a) on its own initiative; or
(b) on the application of any party to the determination.
(2) Sections 153ZEQ and 153ZER apply to the making of a variation of a final determination as if:
(a) an access dispute arising out of the final determination had been notified when the application was made to the Commission for the variation of the determination; and
(b) the variation were the making of a final determination in the terms of the varied determination.
(3) Before making a variation, the Commission may give a draft variation to the parties.
(4) When the Commission varies or revokes a determination, it must give the parties to the determination its reasons for doing so.
(5) A variation or revocation is not a legislative instrument.