The provisions of the Divorce Act, insofar as they relate to the custody of a "child of the marriage," are within the legislative competence of the Parliament of Canada.24Although the matter is not beyond dispute, it is submitted that the jurisdiction to make third party orders pursuant to section 16 of the Divorce Act falls within the federal legislative domain where such claims arise on or after divorce.25
Sections 16 and 17 of the Divorce Act empower a "court of competent jurisdiction" to grant interim, permanent, and variation orders respecting the custody of and access to the children of the marriage. In determining whether a court is "a court of competent jurisdiction," the definition of "court" in section 2(1) applies, and the court must be presided over by a federally appointed judge. If this definition is satisfied, sections 3 to 6 of the Divorce Act deter-mine the province or territory wherein proceedings under sections 16 or 17 shall be instituted.26
An existing custody order made under provincial legislation does not bar the matter of custody from being re-opened in subsequent divorce proceedings, but a custody order granted pursuant to the Divorce Act precludes a subsequent order being granted pursuant to provincial legislation by virtue of the doctrine of paramountcy.27
A custody or access order made under section 16 of the Divorce Act has legal effect throughout Canada and may be extra-provincially registered and enforced pursuant to sections 20(2) and (3) of the Divorce Act.
 Papp v Papp,  1 OR 331 (CA).
 See Kerr v McWhannel (1974), 16 RFL 185 (BCCA); compare Clarke v Hutchings (1976), 24 RFL 328 (Nfld CA).
 See, generally, Chapter 7, Section B, for a discussion of jurisdiction over divorce.
 Adamson v Adamson (1979), 15 BCLR 195 (SC); McKay v McKay (1982), 30 RFL (2d) 463 (Ont HCJ).