In your book of the 50 most important things to remember about SAS that you might not often use, this ranks in the first few pages.
Cynthia showed me this in a class a few years ago, and it has been a constant companion, getting me out of trouble with a number of required result sets.
Unlike Cynthia, this doesn't sit at the front of my memory like basic Proc and Data steps, so I highlighted it in my little black book and am grateful every time I have to refresh my memory.
Kind regards
David