I was checking out the Fare Class Chart in the FAQ and just had a couple questions.

Background: Planning a trip from DCA (or around there) to HNL with the GF and don't want to ride in back (heaven forbid).

Question: Some of the cheapest prices are for T,L,K fares. On the fare class chart it says that for K that this is upgradeable domestic, but no mileage award upgrades. T and L are both deeply discounted rates, but the notes next to them do not stipulate that there is a mileage award upgrade limitation. Does this mean that I can book T tickets and upgrade them using awards? If not, what are the lowest fare classes that I can use to upgrade a ticket? If it's M or whatnot, it seems to me like it would make more sense to just purchase an A fare since it's like $100 more.

Any and all help is appreciated. Thanks!