I regularly have problems with BA when getting tickets issued with code shares. They've recently been good at issuing RTW tickets starting in South Africa, but, as most of you know, the oneworld tool doesn't offer any code shares, so it's necessary to reserve the AA/CX flights and then subsequently, before the ticket is issued, ask BA to change it to include the code shares.

I've had mixed success with this. BA generally give me my choice of code share on the first flight after entering the US, but thereafter they are very inconsistent. I was once told that only the first segment is allowed to be a code share as long as the incoming US flight is with BA, but I can find no rule to this effect.

It's particularly galling after the recent changes to both the BA & AA FF programs to find certain routes with BA code shares are denied when I know they exist.

AA & JL code shares don't appear to be a problem; it's just BA code shares in the US on AA metal.

Does anyone have any info on what the rules actually say, please?