I think you may be getting slightly technical for "regular" flyers who are mainly concerned about wheter they are booking in Economy, Business or First. But yes you are correct, award tickets, no matter what class of service, have special codes which differ from other booking classes.
For instance in UA
A = Discounted Fare First Class
B = Not quite Full Fare Economy with minimal restrictions
C = Full Fare Unrestricted Business Class
D = Discounted Fare Business
E = 1K Special Economy Class Award
F = Full Fare Unrestricted First Class
G = Travel Industry Economy Class fares
H = Higher level Economy Class usually with few restrictions.
I = Also known as "NC
" class. Business Class Upgrade class from Economy
K = Seasonal Economy Promotional Fares/Reduced Fare government contract etc
L = Discount Fare Economy with a lot of restrictions
M = Almost Full Fare Economy with few restrictions
N = Economy Class AWARD TICKET (Better known as 'XY' class)
O = Business Class AWARD TICKET (Better known as 'XC' class)
Q = Discount Fare Economy often with moderate restrictions
R = First Class AWARD TICKET (Better known as 'XF' class)
S = Extremely Low Economy with lot of restrictions, which doesn't always earn miles.
T = Discount Fare Economy often with a lot of restrictions
V = Discount Fare Economy often with a lot of restrictions
W = Discount Fare Economy often with many restrictions
X = First Class UPGRADE AWARD from paid Business (Better known as 'NF')
Y = Full Fare unrestricted Economy class
Its better to be on the ground wishing you were in the air than be in the air wishing you were on the ground. Fly safe!