This US Postal Office uses a combination of two tracking numbers (the POSTNET code and PLANET code ) to track customer’s piece of mail. USPS confirm service provides delivery information about (1) Incoming hard-copy reply mail (Origin Confirm) and (2) Outbound mail going to customers ( Destination Confirm).

A PLANET symbol have 12 or 14 digits. PLANET code symbology is the inverse of the POSTNET codes. The encoding is shown in the below table:


The check digit is based on Mod 10 algorithm. The value of the check digit is that when added to the sum of other digits in the barcode, results in a total that is multiple of 10. For example, the check digit for address code 40123456789 is 1 since 4+0+1+2+3+4+5+6+7+8+9=49 which adds check digit 1 result a sum 50, 5 times of 10.
The PLANET barcode starts with a long bar (frame bar) and ends with a frame bar. Between these two frame bars are the encoded address information followed by a check digit. Each code character is made up five bars, either long or short.

PLANET barcode can be anywhere in the address block portion except the lower right.
For more information, visit http://www.usps.com/cpim/ftp/pubs/pub197/197c6.html.