What exactly does the seat class letters mean?
 

I tried the search but did not find an answer. I am trying to book a ticket to Europe and noticed the class NWA was quoting me was H. Should I be trying for a different class/letter if I hope to get any upgrades? Any clarification would be appreciated.

The Airlines work on a price "ladder". The letter denoted the price that is quoted and each airline is different in what they code the least expensive and so on. The airlines will only let you upgrade certain priced tickets. I believe that Northwest allows you to upgrade a "B" or "y" fare, as these are more expensive tickets. Always call and see what they will do for you. If you don't like the first answer that hang-up and call again, the next person may give you a price and upgrade that you want.

Audie,

You'll find much more information about upgradable fare classes on Northwest on the Northwest board and particularly at the link listed below:

http://www.flyertalk.com/forum/Forum35/HTML/005202.html

This will explain what fare classes are upgradable (almost all fares on NW domesticlaly are upgradable if you're an elite) and what most fare classes mean.

aloha

Welcome to FlyerTalk, trvlngfool.

I like the 'ladder' analogy.