Another poster shared this link: http://www.highprogrammer.com/alan/numbers/dl_us_shared.html http://www.highprogrammer.com/alan/numbers/dl_us_shared.html It h

Another poster shared this link: http://www.highprogrammer.com/alan/numbers/dl_us_shared.html http://www.highprogrammer.com/alan/numbers/dl_us_shared.html It has the encoding formula for Wisconsin, Illinois, and Florida (which match the parent's comment) but there may be others.