CAD
Well, you've hit all around it, and if I don't drop the answer I was wanting,
everyone will get on my case for letting it get to hard. You went into the
technicalities, which I wasn't intending.
It's called Reverse Polish Notation (reverse for the reasons you mentioned)
because no one could pronounce the mathematician's name… or remember how to
spell it. "RPN" was a compromise.
This started with the "Watanabe" plotter name question, which made me think of
the poor Pole who never really got the credit he deserved.
Rick