Code 49 was developed to fill a need to pack a lot of data into a very small symbol. Code 49 accomplishes this by using a series of barcode symbols stacked one on top of another. Each symbol can have between two and eight rows. Each row consists of a leading quiet area; a starting pattern; four data words encoding eight characters, with the last symbol a row check symbol; a stop pattern; and a trailing quiet area. Every row encodes the information in exactly 18 bars and 17 spaces, and each row is separated by a one-module high separator bar (row separator).
The code is a continuous, variable-length symbology that can encode the complete ASCII 128-symbol set. Its structure is actually a cross between UPC and Code 39.
Valid characters: ASCII-characters between 0..127