Anyone got any spare codes they wouldn’t mind donating? Didn’t end up preorder as thought it was released later, oh how wrong I was. Will be picking it up on release/day after though! If you do have any spare codes, please feel free to PM them to me! 
I would, but I gave all my Dorito codes to my other friends. I should also mention, those dorito codes can be used twice(on two different accounts). So if you know anyone that has used Dorito codes, hit 'em up.
There is a trading section
https://forums.halowaypoint.com/yaf_postst124084_The-Halo-4-Bonus-Trading-Station.aspx