What Do All The Different Cabin Class Letters Mean?

UA is very similar to CO, then. As it mentions there, H is the highest discounted economy fare, and it’s that class and above that allows you to upgrade to business on international travel.

I just got a genius explanation off of airliners.net, so if you are interested:

The different letters are fare classes – and determines how much you will pay for your flight. In your example, J, D and likely Z are seats in the business class cabin….J is the usual designator for full fare business, D is discounted business, Z is another variation. The other letters are all economy class fares, Y is full fare economy and likely H being the highest discounted economy or excursion fare and so on. Q at one time was the lowest economy fare rate, but that has changed. Lots of airlines are also, at the moment, revising their fare letter designations….I suspect that this is a CO flight and they have changed many of the codes in recent months with lots of new letters introduced and others will eventually be dropped (ie, what was Q class is now the X class, V became U, etc, etc – what a mess.) The numbers next to each letter represent the number of seats that can be still be sold in each fare class, in this flight, the cheapo tickets are gone……when the number 9 is used, it means that 9 OR MORE seats are still available, ie, there are more than 9 seats in economy available on this flight.

There are additional letters that you do not see, for example on CO you can upgrade your H class ticket on overseas flights to Business First for 40,000 miles, and then you will be ticketed in R class.

The basic letters are P or F for First Class, C or J for Business Class, and Y for Economy class……the rest is fare stuff that can be specific to an airline.

I’m not familiar with the numbers.

I see, that’s what I thought, do you know what the numbers represent?
They never seem to go any higher than 9, and sometimes if I know the aircraft type on the route the numbers just don’t add up.
i.e an aircraft with capacity of about 100, add up the numbers and it comes to more than 100!

The different letters represent different levels of fare class, i.e. price. I don’t think there is a benchmark for this, as different letters stand for different classes for particular airlines. I know on United, Intl economy class can be upgraded only with H-class or above. This is slightly lower than full-fare economy.