Code 93 was developed in 1982 as a high-density, variable-length symbology that combines both Code 39 Extended and GS1-128 elements to enhance overall encodation. This barcode can contain 43 different data characters — numbers 0-9, letters A-Z, six symbols (minus, plus, period, dollar sign, backslash, and percent), and space. In addition, Code 93 uses five special characters which can be combined with the common 43 data characters to represent all 128 ASCII characters.
The “93” designation refers to the fact that each encoded character is constructed using nine modules that are arranged into three bars with adjacent spaces. This code also requires two checksum characters, often called the “C” and “K” characters, and in most cases a human-readable form of the encoded information is printed below the barcode itself.