Direct viewing and editing of cash flows.
I certainly can’t fault HP for the hoops you have to jump through to verify that your cash flow entries are correct. Or for the fact that you may well have to start over from scratch if you forget one in the process, much less have to delete a cash flow. It was the 80s.
But this is 2009 and the introduction of visual cash flow editing in versions 1.3.0 and 2.3.0 sweeps away the cumbersome, error prone, and somewhat mysterious ways of the 12. The video above provides virtually all you need to know about how this feature works and there are written instructions on the Calc-12E FAQs page.