I too have recently booked several HUAUPN flights that CO.com lists simply as 'A'. When calling I was told that this is an instantly upgradeable coach fare that posts miles as an 'A' fare. Miles on CO have posted that way. I was also told that in the event of IRROPS it is considered paid 1st, and surperior to a Y-up. FWIW IAH--> ANC was $20 extra each way if I wanted it to be a "True" A fare. 2 different PPlat agents did not know of any way this would be interior to purshasing a regular 'A' fare. They weren't positive about FF miles for GS but thought they would count (agents admitted it was an educated guess and they did not know for sure).