<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by stdupree:
That's tres useful. Do you also know the codes for international flights?
-steve</font>
International is a little different.
First, this whole thing varies by airline. Only a few airlines can you see upgrade seats available (for instance, CO works the same, but DL does not).
For international on US F is FC (on A330 only) and then J and C I believe are the Envoy codes. They are listed in order, from FC to coach, and the first coach class is always Y. Anyway, upgrade Envoy seats are not shown this way (they are O class), J and C are both paid Envoy.