What do U.S. Postal Service bar codes mean?
Perhaps this report needs some minor updating.
They’re here. The barcode numbers are divided into these groups, and any printed code can contain only the ZIP (5 digits), ZIP plus (5+4 digits) or DPT (Delivery Point, 5+4+2=11 digits). FYI, the postnet barcode also appends a checkdigit for each configuration.
The 9 ZIP plus digits are sufficient to narrow the address range to a single side of a single block in a typical neighborhood. Large mailers may have their own ZIPs, and large office buildings may have several.
The DPT’s final 2 digits are usually created from the final 2 digits of an address. For example, if you live at 123 Anywhere Street, ZIP 94235-3425, “23” would be appended to 94235-3425, derived from the “123” of your address. This is sufficient to give you a number for your house only, about “as specific as phone numbers.”