Respondent on application under section 20 or section 20A
19. –
(1) The respondent on an application for the variation or revocation of an order under section 20 of the Act shall be the party to the marriage in question other than the applicant and, where the order requires payments to be made to or in respect of a child who is 16 years of age or over, that child.
(2) The respondents on an application for the revival of an order under section 20A of the Act shall be the parties to the proceedings leading to the order which it is sought to have revived.