The appearance of an author-written addendum [3] to the paper [2] made our correction note [1] to that paper superfluous and hence it is no longer available here.

[1] Dror Bar-Natan and Ofer Ron, A Correction to "Groups of Ribbon Knots" by Ka Yi Ng, no longer available.
[2] Ka Yi Ng, Groups of Ribbon Knots, Topology 37 (1998) 441-458.
[3] Ka Yi Ng, Addendum to "Groups of Ribbon Knots", arXiv:math.GT/0310074.