PDF417 is a type of 2D barcode, it is a stacked linear barcode symbol format used in a variety of applications, primarily transport, identification cards, and inventory management.
PDF stands for Portable Data File. The 417 signifies that each pattern in the code consists of 4 bars and spaces, and that each pattern is 17 units long.
Each symbol also has start and stop bar groups that allow the code to be easily identified.
PDF-417 can store up to about 1,800 printable ASCII characters or 1,100 binary characters per symbol. The symbol is rectangular; the shape of the symbol can be adjusted to some extent by setting the width and allowing the height to grow with the data. It is also possible to break large amounts of data into several PDF-417 symbols which are logically linked. There is no theoretical limit on the amount of data that can be stored in a group of PDF-417 symbols.
The capacity of PDF-417 can be helpful in applications where the data required must be contained within the barcode label itself item, where a host database is not available for a quick reference look-up.
The maximum data density is determined by the smallest elements which can be reliably printed and scanned. Using the smallest recommended element size of 0.0075 inch wide and 0.010 inch high, the maximum data density in the binary mode is 686 bytes per square inch (106.2 bytes per square centimetre). In the printable ASCII mode the density is 1,144 characters per square inch (177.2 characters per square centimetre).