I saw an ad on TV for that really stupid "commemorative" Liberian metal "bill."

"The first twenty dollar bill to display two different numbers adding up to twenty ~ 9 and 11!"

They also represent the item as featuring "99.9 Silver Plate" [emphasis mine].

A note on the Batman review: Batman's "Gotham City," like Superman's "Metropolis," has always represented New York City, but this new film was quite clearly shot in Chicago...