Furthering the callsign confusion bit, even though the ticket trip number says ie LHR-JER BAW 16xx, the callsign can and was different, as BA with so many more have converted to a Callsign Numbers Letters for RTf confusion purposes. The EASY way to explain is by hearing an EASY checkin, it currently starts errrrrrrr........... while they find the new variant.
For Blair the callsign still will be Speedbird, but the flight priority will be higher than any normal flight, therefore being exempt from all flow regulations and arrival delays. At ATC we have the appropriate priority catergory written on our lovely paper strips, but this doesn't affect/get transmitted over the RTF in any way.