Originally Posted by
polrjoy
Wow, I didn't know this. When booking class was not displayed, I always assumed I could just use the first letter of the ticket's fare basis. Now I know I was just lucky to have earned miles on my flights!
All AM revenue tickets are in mileage earning class.
Another example. An airline says JL publishes a fare from AAA to BBB but BBB is not served by JL. So it requires interline partners like AA AC or B6. For a given fare, it has different booking class for different airlines.
Another example, there was a good deal premium fare R on CX from JFK to MLE. R is the second lowest class for PE, but the fare allows some shorter segments booking into I class (discount business). So jfk I yvr r hkg I mle I hkg R yvr I jfk despite it being R fare.