Thanks for the tip, Sapper.
That got me on the right track and I found this related information, which basically says Canadian Headquarters staffs were separated into "G" Branch (Operations), "A" Branch (Administration) and "Q" Branch (Logistics). These applied at brigade, division, corps and army levels so, I suppose that all staff officers must have worn these brassards.
https://www.canadiansoldiers.com/ran...ffofficers.htm