Abstract: A bar code for mail pieces uses bars each of which has four possible states. Two different bars indicate the start of the code and the same two bars in the same order indicate the end of the code. A data content identifier follows the start bars and this indicates the structure and length of the following data field so that when the code is read it will be recognized and read properly. The use of the data content identifier allows the code to be used for different customer and Post Office applied applications in which the code structure, length and content varies. The data field may contain a postal code with or without an address locator, a machine ID, customer information and service information. The code may include a country code field for mail pieces that are being mailed to a different country. The code may also include a field indicating whether the codeword is complete or whether it has to be concatenated with a preceding or subsequent codeword.