Here's a primer for you.

1. Full fare first class is either F or P, depending on the airline. P is Premium First. Some airlines feel their First Class is better than other airlines, or it's a different configuration. United used to call their SFO-JFK and LAX-JFK P class, as it had lie-flat seats. It's their P.S. service.

2. Full fare business class is C or J. Singapore calls theirs J class, and I believe BA does as well. United calls it C

3. Full Fare Economy is Y. British has a premium economy ( not to be confused with United's Economy Plus ) that is a separate cabin, and books as W class.

From there, each airline diverges a bit.

At United, and many of the Star Alliance Partners,
it goes like this

A = discounted first class, used for Around the World fares, or the YUP and QUP tickets. Same seats, they just limit the number sold at the discount.

D = discounted business class, restricted number of seats sold. These can be upgraded to F with miles or certificates.

Z = lower discounted business class, cannot be upgraded

B = full fare economy, may have restrictions on the number of seats sold. Many times the last seat on the plane goes at the Y fare, not B. Otherwise, pretty much the same as Y.

Y and B can be upgraded to business or first with fewer miles, and are generally refundable, can be changed with no penatly.

M, H, Q, V, W, S, T, L, K are discounted economy fares. M and H can be upgraded with miles internationally. Most of the others can be upgraded with miles domestically.

This is where you will find the sale fares, bereavement fares, etc. Advance purchase, non-refundable, fee to change type fares.

Other airlines differ. On Continental, B used to be a very low fare. Haven't checked lately, as i haven't worked in reservations for 3 years.

Then you get the "free" seats, which on some airlines are O, I, R, or X. On United, the discounted free seats are XY, XC, and XF. If you have to use a standard award ( more miles ), they book in F, C, and Y.

The first letter of a fare basis is the most important. It tells class of service, and where it ranks in that class. F is higher than A. C is higher than D. Q is higher than V.

It might not mean anything to you, but to inventory and pricing, it does.

You can also have numbers, which tell how much advance purchase you need. Then more letters. Again, it doesn't mean much to the general public, but to travel agents, reservations agents, and inventory/pricing people, there is a meaning to it all.

Confused yet?

Frances

Formerly United Airlines. Laid off again, so I'm retiring.