Trinary $1

During the war, the United States issued special currency in areas they believed could be overrun by the enemy, so they printed special notes that they could instantly "devalue".
They used brown ink for the seal and words HAWAII for the notes circulation in the South Pacific, and Yellow ink for those circulated in North Africa. An interest piece of history that you may wish to read up on.

 

Log in or Sign up to hide this ad.

Here is mine. They are still fun to find

 

Similar here. It's no different than squirreling away a few bucks to save, say an emergency fund. A coworker of mine thought I was a little nuts bringing back a set of perfect notes obtained from circulation in Japan - A 10,000 Yen, 5,000 Yen, and 1,000 Yen, worth about $150 all together at the time - rather than exchange them back for dollars. I said it was no different than stashing away $150 to save but that I would get to enjoy them as well.