Originally Posted by
mnredfox
What I meant was there used to be a way to search of DL had R avail on DL.dumb by clicking on upgrade. And the search results used to return "upgrade available" or something like that. I can't figure out how to do that anymore.
But flight stats does not show RU or OU class (or whatever it is).
AFAIK you can still get the "upgrade available" response, but only within your window or if you do a (dummy) booking for a full Y fare. One problem is that it can be difficult to make delta.dumb show you the full Y fares since often there are cheapeer G A P fares or even a refundable/flexible B.