For lack of a better name, I called it 'Project 2013B'. The Zegers/Winograd project *ceased* maintaining the list in September 2021, but I have stepped in and carried on where they left off. To date, there have been 9 matching pairs confirmed. Karol Winograd of Florida started a project (known as the Zegers/Winograd project) of recording all the serial numbers submitted to them by fellow collectors. In an attempt to help currency collectors find a matching pair of notes, Mr. When the government does it it's legal, when WE do it it's called counterfeiting.
There are dollar bills out there circulating with the same exact serial number as another dollar bill! The only difference is one bill has an indicator showing it was printed in Fort Worth, while the DC note does not. The unusual part is they duplicated some serial numbers. In 20, The Bureau of Engraving and Printing (BEP), printed 2013 $1 New York star notes from two facilities, Washington DC and Fort Worth.