Hello SpiderBen, welcome to FT. I don't know if we have one comprehensive post with all the booking codes for the two airlines. A quick search didn't turn up anything for me. Here's what I know:


Class Codes - KLM

A FIRST CLASS
AN FIRST CLASS
B ECONOMY
BN ECONOMY
C BUSINESS
CN BUSINESS
D BUSINESS
DN DELUXE NIGHT
E SHUTTLE SERVICE (EARNS 25% MILES)
F FIRST CLASS
FN DELUXE NIGHT
H ECONOMY
HN ECONOMY
I DISCOUNT BUSINESS (EARNS 150% MILES)
J BUSINESS (EARNS 150% MILES)
K ECONOMY
KN ECONOMY
L K ECONOMY
M ECONOMY
N ECONOMY (EARNS 25% MILES)
P FIRST CLASS
Q ECONOMY
R ECONOMY
S FULL-FARE ECONOMY (AKA Y)
T ECONOMY
U SHUTTLE SERVICE
V ECONOMY (EARNS 25% MILES LONGHAUL)
W ECONOMY
X ECONOMY
Y ECONOMY
YN ECONOMY
Z BUSINESS (EARNS 150% MILES)


Class Codes - AIR FRANCE

A First - Award
AN FIRST CLASS
B ECONOMY
BN ECONOMY
C BUSINESS
CN BUSINESS
D BUSINESS
DN DELUXE NIGHT
E ECONOMY
F FIRST CLASS
FN DELUXE NIGHT
H ECONOMY
HN ECONOMY
I ECONOMY
J BUSINESS
K ECONOMY
KN ECONOMY
L ECONOMY
M ECONOMY
N ECONOMY
O Business - Award
P FIRST CLASS
Q ECONOMY
R ECONOMY
S STANDARD
T ECONOMY
U ECONOMY
V ECONOMY
W ECONOMY
X Economy - Award
Y ECONOMY
YN ECONOMY
Z BUSINESS


I'm afraid I don't know enough about AF to annotate their fares, though I'm sure someone else can.