Queen's Personal Canadian Flag

The Royal Standards of Canada are a set of uniquely Canadian personal flags approved by the Queen of Canada for use by members of the Canadian Royal Family. They are used to denote the presence of the bearer within any car, ship, airplane, building, or area, within Canada or when representing Canada abroad. There are six personal royal standards, one each for the Queen, the Prince of Wales, the Duke of Cambridge, the Princess Royal, the Duke of York, and the Earl of Wessex, as well as one standard for use more generally to denote the presence of any member of the Royal Family who has not previously been provided with a specific personal standard. The flags are part of a larger collection of Canadian royal symbols.

The Royal Standard, also called The Queen's Personal Canadian Flag, is a heraldic banner adopted and proclaimed by Queen Elizabeth II in 1962 for her use in her capacity as Queen of Canada. With its introduction, red and white, first proclaimed by George V in 1921, became entrenched as the national colours of Canada and it was added to the Canadian Heraldic Authority's Public Register of Arms, Flags, and Badges on 15 March 2005. Different standards are used by Elizabeth in some of the other Commonwealth realms and she holds another banner for use as Head of the Commonwealth.

...
Wikipedia