All of the books in Alyosha's library, curiously, are printed; some more roughly than others. The same printer's mark which Reynard had displayed to Waver is evidenced on the interior of the covers. And! Should he happen to look closely... hidden in the aqueous surface design of the inside of the front and back cover, if he scrutinizes it just so, he'll see brief messages! In the newest books received into the library will be these:
no subject
> 'ISENGRIM ALIVE, EXECUTION IMMINENT'
> '14TH SIGIL LOCATION IDENTIFIED'
> 'EMERGENCY COVENANT MEETING, WREATH FESTIVAL, TREUN'
But each book will have other short messages; those obviously printed in the same batches will bear repeats.
OOCly, Waver is not the only person to have this information.