How to determine my booking class?

[RocketMan]

I bought a return economy Etihad ticket (SYD-IST) through STA travel. I'm trying to determine which FF program to sign up for (I'm not a member of any at the moment), knowing my booking class will help me decide which program gives me the most points. I'm tossing up between VA, Etihad Guest and AA Advantage.

How can I determine my booking class? It's not stated on my paperwork supplied by STA. All I know is that it's an economy seat, but I'm sure what flavour of economy.

Thanks

 

[Boris spatsky]

I used STA in September. It is normally listed on the paperwork (but may be obscure - look for random letters in the flight details, sometimes up to 6). Anything?