Sch 1 para 16
(1) In this Schedule “ child ” includes, in any case where an application is made under paragraph 2 or 6 in relation to a person who has reached the age of eighteen, that person. (2) In this Schedule, except paragraphs 2 and 15, “ parent ” includes— (a) any party to a marriage (whether or not subsisting) in relation to whom the child concerned is a child of the family, and (b) any civil partner in a civil partnership (whether or not subsisting) in relation to whom the child concerned is a child of the family; and for this purpose any reference to either parent or both parents shall be read as a reference to any parent of his and to all of his parents. (3) In this Schedule, “ maintenance calculation ” has the same meaning as it has in the Child Support Act 1991 by virtue of section 54 of that Act as read with any regulations in force under that section.