The PLANET barcode is a two-state barcode. Its structure is like that of POSTNET barcode. It was used by the US Postal Service to identify and track pieces of mail during delivery - the Post Office's "Confirm" services.

A PLANET barcode has 12 or 14 digits. It consists of a series of tall and short bars. PLANET Code digit symbology is the opposite of POSTNET Code digit symbology, i.e., each PLANET Code digit uses three tall and two short bars.

PLANET Codes must begin and end with one long "framing bar". All PLANET Codes include a check-sum digit.

An example: