rsc often complains about my choice of bookmarks - scraps of paper, airline tickets, etc. instead of legitimate bookmarks of which we have plenty. The other day I took a BreadMachine cookbook from the library and in it I found this index card:
I wish the library didn't preserve the privacy of prior book borrowers because I'd like to meet this person. This card is just like something I'd do.

Other finds from inside books
Either way, I like it.