“up on top” vs. “up top”
My wife (from northern Virginia) uses “up top” where I would use “up on top”. For example, where I (from Wyoming) would say that “the box is up on top of the refrigerator”, my wife leaves out the word “on”, and she would say that it is “up top of the refrigerator”. She (and her family) are the only people I know who do this, and this leads me to believe that it is a regionalism. Is it?