Gave up my upgrade on a RJ from YYZ to EWR (1hr flight) to go earlier and use an upgrade certificate on EWR to SEA (6hr flight). Booyah!
I was trying to use the upgrade on my original flight but it was looking hopeless
HUACA = hang up and call again
SDC = same day change
Upgrade queue jump – taking advantage of flaw in UA’s upgrade process to grab an upgrade before the automated process gives it to a (more) eligible member