[Dan in Pasadena]

I suppose the practical realities of this situtation if you were going to keep the money is the average person (like us) wouldn't KNOW if it were marked...but that can be researched.

You'd have to put it in a safe deposit box and let it sit a long time...perhaps taking small amounts out for use (AFTER you figured out it was unmarked) and of course never depositing it in an investment or interest bearing account in amounts greater than $10,000.

I don't know. I'd figure it out. It would (in a way) be a fun project to do....from a public library computer!