Channel Code is a family of linear (one-dimensional) bar code symbols designed for encoding strings of 2 to 7 digits in the least symbol length possible. Reference decode algorithm and optional check calculation are included in this document. There are six defined sizes of the symbols. They range from "Channel 3" which can number up to 27 items in just 22 "X" of total symbol length up to "Channel 8" which can number up to 7,742,863 items in a space equivalent to 42 "X". There are also a number 'composite' symbol formats defined that offer enhanced capacity and/or security.
Channel Code symbols can be made autodiscriminatable from many other symbologies, but they are not autodisriminatable from each other in a reliable manner. It is strongly recommended that applications using Channel Code select to use, and their readers be programmed to decode just a single channel or composite format.