In the .PDF, the page titled 'Section 2: The Reference Guide' has a code at the bottom...
Here's a re-paste from the PS1 ISO I have: Please look up the page listed below in your Game Manual, and enter the eight digit code listed at the bottom of the page..EG: Page 13 of Game Manual Code: 3994-9668.Please Enter the Code from Page .
Notice the last line says Page and then there's a blank spot. That's where a number will be, the space is like a place holder.
If I can just find where to actually input a number sequence, I can likely crack it.