I am beginning to wonder if we are actually secretly agreeing but we are using different words to mean the same thing
. So let me put some definitions forward:
Prime code: The preferred booking class of the whole fare, for instance an I- fare on BA has I, a YUP- fare on UA has A, et c. But, the fare will specify other booking codes on a per-sector basis according to its booking code exceptions table.
Booking code: The actual booking class used to make the reservation on an individual leg, for instance an F- fare with prime code F may still book into Y on some legs. The actual booking code is calculated from a table that is attached to the fare.
Originally Posted by
FrankTalk
Yes, but this is not "setting the fare", at least not more than changing the date or route or class of service, because diff availability can also "set the fare". /F carrier.origin+destination.farecode sets the fare, but not the booking codes
I agree with this.
Originally Posted by
FrankTalk
/f bc=x sets the booking code (edit: RBD I guess) on at least one of the legs.
That's where we diverge on how we think this works (assuming we are not actually saying the same thing).
I think to get to the bottom of this we need to find a case which would distinguish between our two positions (or we could just ask
ITA Hacker 
).
This is, again, because DUB-LHR even in J will not allow combinations with transatlantic fares. As soon as ITA can break the fare it will price both ways and will give you the cheapest option.
But it doesn't need to insert a fare breakpoint to book DUB-LHR into J. It can take an I- through-fare on DUBNYC and use that to book into J on the DUB-LHR leg.
So I believe that bc=J requires the prime code of the covering fare to be J, independent of whatever booking classes are allocated for the sectors. Therefore we have to use a full J fare and this is consistent with what I would expect.
I think, and please correct me if I'm wrong, what you are saying is that at least one leg must actually be booked into J. So then, under your assumption, why not use the cheap I- fare to cover this leg, which happens to book into J on this leg, as specified?
Going over to UA, let's see these two cases. MKE-ORD-LHR-ORD, with MKE-ORD specified /F BC=A. If you select cheapest fares UA will book MKE-ORD in A and the rest of the itin in Y
So this remains consistent with my analysis as well. The fare it found, UAA7AFFN, does indeed bear the prime code A:
Code:
>$LB10
010 MKECHI 05FEB17 UA USD 249.00 UAA7AFFN STAY---/-- BK-A
FARE CLS EXPLANATION BOOK CODES
-------- ---------------------- ----------
UAA7AFFN FIRST CLASS SELL-UP OW NON-REF FARES A
UAA7AFFN APPLIES FOR ONE WAY FARES
UAA7AFFN FOR ADULT
BOOKING CODE EXCEPTIONS
VIA UA U/A PERMITTED A WHEN U AVAILABLE
VIA UA U REQUIRED
The other legs are unrestricted so it can find a cheap combination to cover the rest.
, because 1) it can break the fare in ORD and 2) MKE-ORD in A and ORD-LHR in cheapest possible is less than MKE-LHR in A.
Should you select First Class for cabin (or force A on the ORD-LHR leg too) you'll have an A through fare that costs more:
We agree here, our logic is the same; except that I would say it only needs to obtain a fare with prime code A covering MKE-ORD, it doesn't necessarily have to be booked into A.
Seems /f BC=x doesn't force the actual booking code for any legs but the RBD for at least one leg. If we pick a flight with no F cabin and force A ITA will book in Y with an UP fare:
None of your legs there are in A, so in what respect has it followed your logic? However again, looking at that YAA00UPY fare, the prime code is A (with Y also permissible):
Code:
>$LB18
018 MKECHI 05FEB17 UA USD 600.00 YAA00UPY STAY---/-- BK-A Y
FARE CLS EXPLANATION BOOK CODES
-------- ---------------------- ----------
YAA00UPY ECONOMY UNRESTRICTED FARES A/Y
YAA00UPY APPLIES FOR ONE WAY FARES
YAA00UPY FOR ADULT
NO BOOKING CODE EXCEPTIONS FOR CARRIER - USE PRIME