  We consider ribbon n-knots for n\geq 2. For such knots we define a set of
moves on ribbon disks, and show that any two ribbon disks for isotopic knots
are related by a finite sequence of such moves and ambient isotopies. Using
this we are able to prove that there is a natural geometric correspondence
between ribbon n-knots and ribbon m-knots which is bijective. We also explore a
diagrammatic calculus for such knots. In addition we show that for such knots,
any two band presentations for the same knot are stably equivalent.
