Code 11 is a linear 1D barcode. The character set includes the digits from 0 through 9, a dash ( - ), and a start/stop code. Each character is encoded with three bars and two spaces. Of these five elements, there may be two wide and three narrow, or one wide and four narrow elements. Wide elements represent a binary 1, while narrow elements represent a binary 0. Two check digits, named C and K, are used; often only the first check digit (C) is used when the length of the data is 10 or less characters.
Code 11 is used primarily for labeling telecommunications equipment.