This Part applies in relation to the assessment of child support payable by a parent for a child, subject to:
(a) any determination made by the Registrar under Part 6A (departure determinations); and
(b) any order made by a court under Division 4 of Part 7 (departure orders); and
(c) any provisions of a child support agreement that have effect, for the purposes of this Part and section 142, as if they were such an order made by consent.