ENTER↑ is a misnomer, long live ENTER:

[Les Bell]

(07-07-2014 10:13 PM)Den Belillo (Martinez Ca.) Wrote:  And remember:
Except for memory size and lines of display; the way the 41 does it is best and right.

Absolutely agree, db! And, of course, this is the way it's been, right since the 35.

While there may be a problem with the way it was explained in the 12C manual - accounting types may well have had exposure to some of the weird adding machine logics out there - it struck me as obvious and intuitive from the time I picked up my new 45 back in 1974. If you understand the stack as X, Y, Z and T, then you have the correct mental model.

From all the comments that number the stack levels and mention RPL, it looks to me as though it's the differences between the RPN and RPL command line and stack behaviours that are causing the confusion. They really are two quite different beasts.