Another observation about the QR codes, after going through
http://www.thonky.com/qr-code-tutorial/data-maskingAll codes use mask pattern #2, except for:
- QR code 03 (The corridor is lined with pulsating light bulbs in iron sconces. In an alcove there is a fallen statue with an inscription When azoth and fire whiten Latona, Diana comes unclothed.)
- QR code 10 (There is an iron passageway, it is very dark, you walk slowly with your hand against the wall guiding you... just in case. You come across a fortified iron door guarded by two mechanical gargoyles. There is an inscription on the door The dragon guards the key.)
which use mask pattern #6.
That said, it could just be a coincidence of course.