Originally Posted by
gusd
Unless you do a multiple destination search

, in which case united.com shows UA902 as S9. ....
thats what married segments is all about
Originally Posted by
gusd
... Would doing a multiple destination search consider the connection in IAD a stopover as it's more than 4 hours? And thus leading to the fare being validated differently?
stopover for international trips is >
12 24 hours but the >4 hours may be a factor in this case.
My guess is the multi-destination is not enforcing the married segments (for whatever reasons, in this case) hence the availability.