Thanks Elizabeth...your study of language sounds fascinating. I had never heard those initials before.
As for me, I just rely on my ear to differentiate cockney from Queen's!!
I lived in London for a short time in the early 1980's and I also have relatives-in-law and friends from London so I have been able to differentiate the social and educational differences in British accents. Infact, I have a cousin-in-law in his sixties, who went to private (or as the British so confusingly say: 'public') schools and sounds alot like Prince Charles!