Forgotten Bookmarks

Many of us have had the experience of checking a book out from the library, or buying a used book, and finding something in it that some previous reader had used as a bookmark; an actual bookmark, a bus ticket, scrap of paper, photo... A recent article tells of a site where used bookdealer Michael Popek has posted some example of bookmarks found in books in his store (click here,) like this bookmark for an optometrist found in a 1938 title, Blood and Steel, by Bernhard Menne.