What the standard covers
ISO/IEC 15438 specifies the PDF417 symbology: the start and stop patterns, the row indicators, the codeword patterns, the text, byte and numeric compaction modes, and the error correction levels. It also covers related variants such as compact PDF417, sometimes called truncated PDF417.
PDF417 was developed by Ynjiun P. Wang at Symbol Technologies in 1991. The name comes from its codewords, each 17 modules wide and made of 4 bars and 4 spaces.
Structure and capacity
A PDF417 symbol has 3 to 90 rows and 1 to 30 data columns. Error correction uses Reed–Solomon codes over a field of 929 values, with nine levels from 0 to 8 that add between 2 and 512 error correction codewords.
At its maximum a symbol holds roughly 1,850 text characters, 2,710 digits or 1,108 bytes. The smaller MicroPDF417 variant has its own standard, ISO/IEC 24728.
- Rows: 3 to 90
- Data columns: 1 to 30
- Each codeword: 17 modules, 4 bars and 4 spaces
- Error correction levels: 0 to 8
Editions and use
The first ISO edition was published in 2001, followed by a 2006 edition and the current 2015 edition. PDF417 is used on many North American driver’s licenses and ID cards, on paper boarding passes under the IATA bar coded boarding pass format, and on shipping and government documents.