CMSC (Corps of Military Staff Clerks)

[BEFman]

As part of a cataloguing project for Canadian WW2 cloth insignia a couple of years ago I came across signs to the CMSC (Corps of Military Staff Clerks), including a curved purple shoulder title with white lettering. It was clear that this Corps served some key administrative function at higher headquarters, including armoured, but seemingly not infantry, divisional headquarters. I wanted details of who they were, what they did, when formed, etc., to include as background for the catalogue. I asked a few knowledgeable people and looked at various sources, printed and on the Internet, but came up with precisely nothing. The frustration started an itch that I still feel the need to scratch. Does anyone on this forum know about them, and can they point me to some authority?