Question about AFV names

[Bruce Parker (RIP)]

I've been pondering this question and looking at as much period material as I can find and have come up with a working theory.

I suggest that A, B, C and HQ names were applied to armoured cars up to sometime in 1943, similar to those seen on tanks. At some point in 1943 until the end of the war they were dispensed with and in their place triangular 'A', square 'B', round 'C' and diamond 'HQ' symbols were used. I base this on never seeing a squadron name and squadron symbol used together on armored cars (but always on tanks, and HQ squadron Calgary Regiment 'dingo's' at Dieppe...but that is a tank regiment and not an armoured car or recce one). It's names 1942-43 and symbols 1943-45. I expect Canadian and British armoured car regiments would have followed the same rules.

If I'm right it now needs some documentation, and an answer to the question: why?