7. The Commission may have any document served:
(a) according to all regular methods for making service provided for in the Code of Civil Procedure (chapter C-25);
(b) by forwarding a copy by registered or certified mail, to the addressee at his last known home or business address;
(c) if circumstances so warrant, the Commission may, on its own initiative or upon request, authorize that a document be served by means of a public notice in newspapers;
(d) the Commission may have any document served through a labour relations officer.