Okay, here is what the credit card agencies have to say. If the card is not signed, I have to make sure you sign it and I have to make sure that the signature matches the signature matches the signature on the ID you provide me.
I love this one. My signature changes just about every time I write it. Often, it's a big scribble. Sometimes I write my full first and last name. Sometimes just my first initial and last name. And my signature in the very tiny space on the back of the card is certainly different from my signature on a large space on a credit card receipt. No matter how I sign the receipt, the cashier looks at the receipt, then looks at my signature on the card, then nods his/her head as if to say, "Yup. Perfect match." And there is usually little or no resemblance. When I worked in retail, I did the exact same thing!
Same here. I've got my "fast" signature for when there are 5 people waiting in line behind me. It's basically a scribble. Then there's my fancy signature like I'd put on a resume. And then there's the signature I get when I'm using a plastic stylus on an LCD screen with two gallons of milk and a bag of chips between me and the card reader. And then there's my 1/4" tall signature that goes on the back of credit cards