Originally Posted by CDKing

Id say look for the "operated by" wording on the US site. The operated by normally means it operated by a carrier that is not the marketing carrier. So if it says Operated by American Airlines its likely USXXX and not AAXXX. Although AS site states must be AA ticket stock and if it is US coded the BP will list the US flight number under sold as on the AA BP. Then again if its a flight after the reservation systems are merged it likely wont be an issue