Sad but true.
And besides, considering the way you bombard us with your popular culture, we have no other option but to learn it in great details.
Anyway. When I included the "Yankee" option, YES, I know what a Yankee is, and YES, I thought to that particular area of the USA.
It's exactly like the distinction I made between Scots and Gaels, or what I tried to explain with India, since Indian-English is NOT a genuine English accent, at least linguistically speaking.