I brought a donut and the guy gave me a recieipt for the donut. I don't need a receipt for the donut, I give you the money, you give me the donut, end of transaction. We do not need to bring ink and paper into this. I can not imagine the senerio where I would have to prove that I broughrt a donut. Some skeptical friend. Don't even act like I didn't get that donut. I got the documentation right here.