Following up on previous discussions, I was also doing some research on the actual mechanism to appoint the Governor General of Canada.
The office of the Governor General is currently constituted under Letters Patent issued by King George VI in 1947, a copy of which may be read
in this link .
Under the Letters Patent, the GG is appointed by a commission under the Great Seal of Canada. The LPs instruct then that the commission must be read and published in the presence of the Chief Justice and the members of the Queen's Privy Council for Canada upon which the GG must take the oath of allegiance to the Queen, her heirs and successors, and the other specific oaths prescribed for the office.
Customarily, upon being sworn in, the GG causes a proclamation to be published giving notice of his / her inauguration. The link below shows the proclamation issued by GG Michaëlle Jean and published in the Canadian Gazette to make known her appointment and that she had entered upon the duties of the Office of Governor General and Commander-in-Chief in and over Canada. The link also shows, following the text of the proclamation, a copy of the actual text of her commission under the Great Seal of Canada and the royal sign manual.
https://web.archive.org/web/2011081...ves/p1/2005/2005-09-27-x8/html/extra-eng.html
It is fascinating to have an old-fashioned monarchy like Canada in North America. Too bad most Americans are completely unaware of the traditions of the Canadian monarchy.