Let me break it down the way I did before (but this time not from memory).

Full Fare Business (usually international): J, C (codeshares)
Discounted Business (usually international): D, S, I (codeshares)
Full Fare First (domestic): F
Discounted First (domestic): A
Coach (upgradeable internationally): Y, B, M
Coach (upgradeable for non-elites or with miles or PMUs domestically): Y, B, M, H, Q, K
Coach (not upgradeable except for elites flying domestically using complimentary medallion upgrades - not with PMUs or miles even for elites) L, U, T.

Note that some domestic flights have an international designation (i.e. fare classes for premium cabin will generally be J or D, not F or A.). These flights may or may not have a premium cabin with a "business" configuration. Also, remember that on some short (e.g. Caribbean and Mexico) international flights, medallions can upgrade any fare class, just like domestic flights).

And of course there are the award and upgrade fare classes as well, I'm not sure I have all of these correct.

V: inventory for using complimentary medallion upgrades on domestic flights.
X: inventory for using Complimentary medallion upgrades on domestic flights that have an international flight number
G: inventory for domestic upgrades using miles or PMUs
Z: inventory for international upgrades using miles or PMUs
N: domestic award inventory?
R: international award inventory?

I'm sure that a search on FT would bring up a full list posted by someone else.