This is second time I've used IB (J) as an AA codeshare and still am not able to get an IB PNR. It appears you can check-in for IB (on their website) using name/Ticket number, but to update a booking (seat selection, meal selection, advance passenger info - etc) you need the IB PNR. AA gives me a 5 character PNR that does not work - I was told last time that AA codeshares are held in a separate DB and only merged into the IB DB at the last moment. (I have no idea if this is accurate or not.) I was able to select a seat (initially) via AA site, but I really wanted to very INTL doc info and select a meal. Anyone know if this is possible for AA codeshare?