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Now you don't need to look them up, all are in the PDA's Emails or Audio files, only the 2 free stuff lockers and Security Chief Door are hard to find cuz the free stuff is the email name (0508) and is Security Chief Door listed at 1 code but is said the can't use that and 1 number is changed in it (931) on top of that you get the PDA a few levels before you get to the door!
O ya, you don't need to kill anyone for the locker code (I think), only for the PDA's Achievement! And if your going for the locker Achievement you can miss 3, I missed 1 and opened 2 more after I got the Achievement!