A strange gold number...?

[Soushi_Grapple]

A friend of mine brought this to my attention:
http://img140.imageshack.us/img140/33/dscf3045.jpg
The one on the right has a gold number thing, the one on the left doesn't. He picked these up the same day, I believe at launch. I checked mine, it has that number as well.

I just wondered if it means anything inparticular or was related to the place that gave it out (in my case it was Gamestop)

Thanks guys~

[Enzeru]

They should all have the number...It's the number of printing. Mine has it, as well. If it doesn't an error might have occurred during manufacturing.