characters are represented by sequences of two characters of Code 93. This encoding is the same as Full ASCII Code 39, except that four special-purpose symbols are used, rather than reassigning $, /, + and %: References http://www.barcodeisland.com/code93.phtml Bar code Island's description of the code. External links Morovia Library Code 93 Specification This includes the checksum computation algorithm. Note that "C" is included in the computation of "K". Code 93 Technical Specification Barcodes