My rec is logon to Flying Together and read the rules as they do have specific caveats and change on occasion so you don’t F this up and lose pass benefits (which does happen)…

This excerpt pretty much sums it up; “When traveling on a myUAdiscount ticket you may not standby for flights included in their ticketed itinerary and/or cancel the confirmed reservation to revert back to a space available listing on the same day”; also, “a pass rider may not cancel the confirmed reservation to revert back to a space available listing for the same day with the same destination or nearby destination, like LAX and SNA or MIA, FLL and PBI, just to name a few examples”. My take, If United considers an airport a satellite airport like IAD/DCA/BWI, EWR/JFK/LGA, LAX/SNA/ONT, etc etc then it’s probably not allowed… but that’s what I use to stay clean.

Really the big key to this policyis “same day”… non-rev out the day prior to your revenue ticket and its fine… personally once I buy I just stick to it.