Thread:Unok/@comment-4556650-20150523122636/@comment-3544775-20160517222054

There was some official site for such codes, but it's a bit hard to look into it. It was more like if you knew the code to look for info on that product. But like I said, amazon usually have them. I added them, saw the amazon one you added and that one don't have it. Usually those that have 【Amazon.co.jp限定】 don't have ean, as they are amazon exclusive (exclusive part was that they included e deca can badge). But if you look at their other versions of vol1, you will see they have EAN, same with the rest of the vols.

Often I also see that azn code, not really sure what it is, but sony shop, aniplex shop, official site, hmv and many other also include it (example ANZX-11671). I assume it's some Japan exclusive code or something. The strange thing is amazon of all don't mention it XD