| Value | Encoding |
|---|---|
| 1 |  |
| 2 |  |
| 3 |  |
| 4 |  |
| 5 |  |
| 6 |  |
| 7 |  |
| 8 |  |
| 9 |  |
| 0 |  |
POSTNET (Postal Numeric Encoding Technique) is a discontinued technical standard defining a barcode symbology used by the United States Postal Service to assist in directing mail. The ZIP Code or ZIP+4 code is encoded in half- and full-height bars. Most often, the delivery point is added, usually being the last two digits of the address or PO box number.
The barcode starts and ends with a full bar (often called a guard rail or frame bar and represented as the letter "S" in one version of the USPS TrueType Font) and has a check digit after the ZIP, ZIP+4, or delivery point. The encoding table is shown on the right.
Each individual digit is represented by a set of five bars, two of which are full bars (i.e. two-out-of-five code). The full bars represent "on" bits in a pseudo-binary code in which the places represent, from left to right: 7, 4, 2, 1, and 0. (Though in this scheme, zero is encoded as 11 in decimal, or in POSTNET "binary" as 11000.)
- ↑ Publication 25, Designing Letter and Reply Mail (PDF). United States: United States Postal Service. July 2003. pp. 37–56. Archived from the original (PDF) on 2005-01-18.
- ↑ United States Postal Service, Domestic Mail Manual 708.4 - Special Standards, Technical Specifications, Barcoding Standards for Letters and Flats. "Postal Service Relaxes Upcoming Requirements for Automation Prices". Archived from the original on 2011-03-08.
- ↑ Commons
