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Article 4473 of comp.misc: From: balcer@gypsy.siemens-rtl (Marc J Balcer) Subject: Re: U.S. Postal Service Zip+4 bar code: what is it? Summary: Summary of Responses and Other Information Message-ID: <3767@siemens.UUCP> Date: 16 Nov 88 18:47:18 GMT Organization: Siemens RTL, Princeton NJ

Thanks for all the replies to my question about USPS bar codes. Here's a summary, as well as other information I researched myself.

The code itself is a 2-of-5 code, with leading and trailing "1" bars and a checksum digit.

The five binary digits represent 7, 4, 2, 1, 0. Each decimal digit in the zip code is represented by the following pattern: 0 = ||... 5 = .|.|. 1 = ...|| 6 = .||.. . represents a short bar 2 = ..|.| 7 = |...| | represents a long bar 3 = ..||. 8 = |..|. 4 = .|..| 9 = |.|..

Either a 5-digit or 9-digit (Zip+4) code may be encoded using this method. The actual bar code contains either 6 or 10 digits. The last digit is selected such that the sum of all of the digits (including the last one) is a multiple of 10.

For example, the zip code for Siemens is 08540:

1. The check digit is 3. (0 + 8 + 5 + 4 + 0 + 3 = 20)

2. The bar code is

|||...|..|..|.|..|..|||.....||.|

|0----8----5----4----0----3----|

According to the USPS Domestic Mail Manual (Section 917.528), the bar code is placed at the bottom of the envelope so that the first bar is between 3.875 and 4 inches from the right edge of the envelope. The baseline of the bar code must be 0.25 inches from the bottom of the envelope.

A "1" bar must be 0.125 inch (plus or minus .010 inch) high. A "0" bar must be 0.050 inch (plus or minus .010 inch) high. All bars must be 0.020 inch (plus or minus .005 inch) wide. Bars should have a nominal horizontal spacing of 21 to the inch, plus or minus one bar.

The USPS does give bulk-rate discounts for presorted and bar-coded mail. The best discounts are for Zip+4 presorted and bar-coded.

Check with your local postmaster before sending your own bar-coded mail. --------------------------------------------------------------------------- Marc J. Balcer [balcer@gypsy.siemens.com] Siemens Research Center, 755 College Road East, Princeton, NJ 08540 (609) 734-6531 ---------------------------------------------------------------------------