Stacked Symbologies

Stacked symbologies evolved as 1D codes — Code 39 and Code 128 — were stacked in horizontal layers to create the multi-row symbologies, Code 49 and Code 16K, respectively. PDF417 followed in 1990 with added features that increased data capacity, improved data density, and strengthened reading reliability by a scanner. These features enabled decoding from scan paths that span multiple adjacent rows while incorporating error detection and correcting techniques. SuperCode, a stacked code that can break data into small packets and create various shaped symbols, is also a member of this group of 2D symbologies.

2D Stacked Symbologies - examples

Code 49	Code 49 was developed by David Allais in 1987 at the Intermec Corporation to fill a need to pack a lot of information into a very small symbol. Labels can be printed by standard printing technologies. Purchase Specification
Code 16K	Code 16K, developed by Ted Williams in 1989 to provide a simple to print and decode multiple row symbology, is mainly used in the health care industry.. (The structure of 16K is based on Code 128). The code is a continuous, variable-length symbology that can encode the complete ASCII 128-character set. Purchase Specification
PDF417	PDF417 is a two-dimensional, multi-row symbology designed to be scanned by laser scanners and linear CCD scanners and used to encode data files with hundreds or thousands of characters in a laser scannable symbol.  PDF417 is used in a variety of applications, primarily transport, identification cards, and inventory management. Purchase Specification
SuperCode	SuperCode is a packet bar code symbology, a variant of a multi-row symbology. There are precise rules for the horizontal placement of symbol characters in a packet, but greater freedom in placing packets vertically and horizontally than offered by a matrix of columns and rows in a multi-row symbology.. Purchase Specification