[quote name='thekrayze']wow, i actually said something true, hot damn,
how or where do you check a codes validity?[/QUOTE]
You can physically enter it on your Xbox 360. It will ask you to confirm redemption (prior to actually redeeming the code), at which point you would cancel out if you were just verifying the code's validity... If you enter the code online it will instantly redeem it (unless you already own the content).
But what I did was just go online to
https://live.xbox.com/en-US/RedeemToken and I entered the code there. I knew that since I already had the beta that it would come up as "You already own this content." and I would be unable to redeem it. Therefore I could check any number of variations of the code and once I found the right one (it only took me 1 try

) it would simply tell me that I had the content already, leaving the code unredeemed for the next person to use.
EDIT: Oh yeah, and BTW: The reason that MS does not use the letter "A" (or the letters "O", "I", "S", etc., and the numbers "0", "1", "5", etc.) is because they too closely resemble other letters or numbers. Especially when printed on paper/packaging as physical printing can be somewhat unreliable. "A" looks too similar to "4", as does "O" and "0", "I" and "1", and "5" and "S", so they just dont use those letters and numbers for codes. Just FYI.
