Originally Posted by
NDman
Thanks a lot Efrem! I was hoping to hear that the classes would have some sort of chronological order to make things easier (e.g. G>K>L>M>etc etc).

I guess it didn't work that way.
Still, that clears up a lot. I definitely have a lot to look up. Many thanks again!
For the large airline forums within FlyerTalk, there may be a wiki or FAQ within each airline forum that lists each airline's sequence of fare classes.
This thread from our United forum is a complete discussion of booking classes on UA; but, as noted, each carrier uses its own codes and order.