I booked a flight with United Airlines. However, some of the flight legs are operated by airline partners of United Airlines.
For example, under one of the flights, it says:
Flight operated by ANA ALL NIPPON AIRWAYS.
If this is an originating flight on your itinerary, please check in at the ANA ALL NIPPON ticket counter.
What does "originating flight" mean? Does it mean the first flight on a multi-leg journey?