Possibly An embossed ID stamp from a foreign currency exchange place. You can see the ID numbers above the S/N. I think it should have been inked but somehow was missed.
Regardless, something that occurred after it left the BEP as others have said. Not an error
Comments
Some kind of embossed seal. Not done at the Bureau of Engraving and Printing.
Thank you
Possibly An embossed ID stamp from a foreign currency exchange place. You can see the ID numbers above the S/N. I think it should have been inked but somehow was missed.
Regardless, something that occurred after it left the BEP as others have said. Not an error