I can help you with that:
C = Long term published Business
D = Long term published Business
Z = Short term published Business
J = Short term published Business
I = Business Award/Redemption (ie UA mileage member into Business)
R = Airpoints Business Award Upgrade class

U = Long term published Premium Economy
E = Long term published Premium Economy
O = Long term published Premium Economy
A = Short term published Premium Economy/Premium Economy Reward upgrade class

Y = Full Economy Flexi
B = Economy Flexi
M = Economy Flexi
H = Economy Flexi

Q = Economy Flexi-Saver
V = Economy Flexi-Saver
W = Economy Flexi-Saver
T = Economy Flexi-Saver

L = Economy Smart Saver
S = Economy Smart Saver
G = Economy Smart Saver
K = Economy Smart Saver
P = Economy Smart Saver (Domestic Grab-A-Seat/Trans Tasman short term Economy Sale) - Generally not valid for Longhaul.
F = Economy Smart Saver (Domestic Grab-A-Seat special ie $1 specials) - short term
X = Economy Redemption/Award (ie Star carrier economy redemption class)
N = staff category - subload/non-subload

Hope this helps.