6.—(1) Section 28D (determination of applications) shall be modified by the substitution, in paragraph (a) of subsection (1), for the words “under section 11 or 12(1)” by the words “under section 16 or 17”.
(2) Section 28E (matters to be taken into account) shall be modified by the substitution for paragraph (b) of subsection (3) of the following—
“(b)where the maintenance calculation in force was made in response to an application under section 7, by either of them or the child concerned.”.