I just purchased (on aa.com) a jfk-zrh-jfk rt 11/26 outbound, 12/1 return (flts. 64 and 65 resp.) The ticket confirmation shows
us air 64 and 65...am I flying on aa or us air? In any event, the bc are the new cabins 1-2-1...the seat map looks nice.
Your ticket receipt shows the operating carrier or it's out of compliance with a ~ten year old DOT rule. There should be absolutely no ambiguity, not in online presentation at itinerary selection, nor on the reservation confirmation, nor on the ticket receipt.