So, given all that has been said on this thread, where does that leave us? It would seem that the most probable explanation is that the discrepancy is due to different inventory being shown in different GDS's, such that ITN and BA can see the A seat, but CX cannot, and that the issue is not the fact that a AONE fare is being used, at least not directly. A separate question is whether or not this discrepancy is deliberate. For example, it's possible that BA is willing to sell A tickets itself, but not through a particular GDS, as it knows historically that A sales through a particular GDS result in lower average revenue (perhaps as a result of a higher proportion of AONE fares), but this is different than the discrepancy being caused by the fare itself.