A case against the x<>y key

[Don Shepherd]

From an RPN keystroke programming perspective, I can't imagine not having and using x<-->y. It was there on the first HP handheld programmable (HP-65) and all subsequent ones, AFAIK, because it serves a legitimate purpose in stack manipulation. It is as necessary as the four arithmetic operation keys, and ENTER.

I would never advise anyone not to use it. Users of these calculators are assumed to know the behavior of each key.