Halo 4 code: Whats it for?

Xbox live just sent me a message with this code, so i redeemed it aaaand what now? What did i get?

ANYONE PLEASE HELP ME!!1

You have unlocked the ability to choose more than the 2 default Specializations.

Once you reach SR 70 that is… like me frozen @ SR 70 for going on 2 weeks now.

If you happen to have another code I’d be happy to take it off your hands.