phantom drive B is explicitly mentioned in https://en.wikipedia.org/wiki/Drive_letter_assignment#Order_of_assignment https://en.wikipedia.org/wiki/Drive_letter_

phantom drive B is explicitly mentioned in https://en.wikipedia.org/wiki/Drive_letter_assignment#Order_of_assignment https://en.wikipedia.org/wiki/Drive_letter_assignment#Order_... the linked source checks out. diskcopy will also do this for you if you give it source = dest.