Call of Duty: Modern Warfare 2 Easter Egg - Hidden Within Hidden

Within the first section of Hidden, in special ops, there are at least 3 easter eggs. These all circle around the writing on the sides of the crates. From the start, step backwards until you are not in the "armory crate." The crate on the right, adjacent to the "armory crate" is red and has the inscription MWCOD, as in modern warfare call of duty, and the numbers beside it are 01337, elite. That box recurs. Now going through the armory crate, head to the right toward the wrecked car. On the car's right side is a beige crate; this crate has the inscription, CALLOFDTY, as in call of duty and has the number 00187. Now in back of the car there is a blue crate, this crate has the inscription INFNTYWRD as in infinity ward, and the number 07734. One more crate has a different inscription but I am unsure if it has any meaning, the letters are PWTLRCHN and has the number 00420 (which could be the joke itself as a Hitchhiker's Guide to the Galaxy reference).