Some of the new USPS 4-state barcodes cannot be read, what does that mean?
The USPS has at least two 4-state barcodes. The All My Papers AMPLIB 4-state reader is for the public use version called OneCode or IntelligentCode. This code allows the mailer to generate private information within the barcode and track it through the mail system by USPS provided tools. The OneCode barcode has 65 bars in each code. The USPS also has a 4-state code applied at the post office with 57 bars on large flat mail. This is not meant to be read by the public and the USPS does not publish the specification.
