Originally Posted by
dvs7310
One point to note, if you're looking at an itinerary with multiple segments, then look at your longest segment first by itself. United.com will only show the lowest of all segments on the itinerary, so for example if you have DEN-LAX-OGG, if LAX-OGG has R open but DEN-LAX doesn't, then you'd still see R0 even though you'd clear instantly on LAX-OGG if you bought the ticket and went to the upgrade screen in your reservation.
That tidbit of info was a life saver! I've been searching practically daily for weeks now trying to find an upgrade-able fair to no avail, however that was because I was searching with connections. First search looking at an individual segment, and I was successful.