4Acquisition of parental rights and responsibilities by natural father
(1)Where a child’s mother has not been deprived of some or all of the parental responsibilities and parental rights in relation to him and, by virtue of subsection (1)(b) of section 3 of this Act, his father has no parental responsibilities or parental rights in relation to him, the father and mother, whatever age they may be, may by agreement provide that, as from the appropriate date, the father shall have the parental responsibilities and parental rights which (in the absence of any order under section 11 of this Act affecting those responsibilities and rights) he would have if married to the mother.
(2)No agreement under subsection (1) above shall have effect unless—
(a)in a form prescribed by the Secretary of State; and
(b)registered in the Books of Council and Session while the mother still has the parental responsibilities and parental rights which she had when the agreement was made.
(3)The date on which such registration as is mentioned in subsection (2)(b) above takes place shall be the “appropriate date” for the purposes of subsection (1) above.
(4)An agreement which has effect by virtue of subsection (2) above shall, subject only to section 11(11) of this Act, be irrevocable.