I am going to St. Thomas from DC in December and I have enough FF points for 2 first class tickets. I look on ITN to see what seats are available and I can't understand the codes.

What the screen shows for availability is
F7 Y7 B7 H7 Q7 W7 G7 V7 N7 K7 Z7 M7

I am confused, I thought A was 1st class and F was upgradeable 1st class. How about award (free) 1st class? Can someone shed some light?