Not sure this is the best place to query, but...
Yesterday a TA in LA said that on the 11:10 am LAX-PHL-MAN flt US "holds" one F seat until 1 hour before takeoff, just in case someone needs a last minute trip to England. She said that even when the res clerks look LAX-PHL it won't show up, it will show on LAX-MAN only. Lucky for me, since my hubby (SP) was able to join me in F. We had split the PNR in the hopes of a better chance of clearing one seat at the window and the second at the gate. He very nicely gave his UG seat to me.
Are there other situations out there like this?
Eileen