Originally Posted by
allset2travel
The oneworld planner (trying to put together a RTW itin) does not allow AA flight #. It shows only IB4226 (op by AA).
In this case, the required booking class on the AA code is likely unavailable while that same class on the IB code is available.
It depends on the requirements of the codeshare. Many types of codeshare require that you be connecting to other flight coded by the same airline. eg, I can't use an AA coded JL flight ICN-NRT unless I am connecting to an AA coded US bound flight.
What is your travel plan? There may be other options available if the AA code isn't useable for that flight.