I thought it was instructive to see that in A1 mode the cell formula magically changed as it was copied, while in R1C1 mode it did not; it was good circumstanti

I thought it was instructive to see that in A1 mode the cell formula magically changed as it was copied, while in R1C1 mode it did not; it was good circumstantial evidence that R1C1 is what Excel uses internally. But then I tried an experiment, deleting a column that was referenced by a formula - the formula was replaced with =#REF! indicating that there's still magical changes being applied.