Things found in used books

[Lord stumbleforth]

What's the strangest thing you ever found in a used book?
Do readers have a word (like flotsam) to describe these things?

[GothAdmin]

I usually find business cards, appointment cards or receipts. However, I did once find a small packet of quite rare stamps tucked in to a mystery novel.

[ShirleyJ]

I found a photograph once, a really old black and white on of a child. I wrote a short story about it based on what I'd read about the Victorians having photographs taken of dead children.
On a lighter note, I've also found a few cinema tickets and a shopping list