For the purposes of this subchapter, the term:
(1) “Petitioner” means a person who seeks enforcement of an order for return of a child under the Hague Convention on the Civil Aspects of International Child Abduction or enforcement of a child-custody determination.
(2) “Respondent” means a person against whom a proceeding has been commenced for enforcement of an order for return of a child under the Hague Convention on the Civil Aspects of International Child Abduction or enforcement of a child-custody determination.