Silent Hill Heaven

Not necessary being stuck in the game because of this.... but I'm failing at understanding something... Didn't find anything about this ( sorry if this was already posted/solved, tho )...
In the Cent. Building: The codes written in the books you find marked with the uv light.... what are they ? is there any use for them ? ( the ones with SQ- XXXXX , for example )

edit- submitted this to the wrong board and I'm failing at removing it... Sorry. -_-

If I understand what you're referring to, I think they're only something like library codes for the books, not anything useful or important. I wondered about it at first, too.