In the barcode arena, AIM has long been the traditional source of the technology standards. The most used of the AIM standards have now been adopted by ISO and can be obtained from the ISO organization.
The ISO bar code standards are:
| ISO/IEC 15417 | Bar code symbology specification – Code 128 |
| ISO/IEC 15420 | Bar code symbology specification – EAN/UPC |
| ISO/IEC 15424 | Data carrier identifiers (including symbology identifiers) |
| ISO/IEC 15424 | Bar code symbology specification – PDF417 |
| ISO/IEC 16022 | Bar code symbology specification – Data Matrix |
| ISO/IEC 16023 | Bar code symbology specification – Maxicode |
| ISO/IEC 16388 | Bar code symbology specifications – Code 39 |
| ISO/IEC 16390 | Bar code symbology specifications – Interleaved 2-of-5 |
| ISO/IEC 18004 | Bar code symbology QR Code |
| ISO/IEC 24723 | EAN.UCC Composite bar code symbology specification |
| ISO/IEC 24724 | Reduced Space Symbology (RSS) bar code symbology specification |
| ISO/IEC 24728 | MicroPDF417 bar code symbology specification |
| ISO/IEC 24778 | Aztec Code bar code symbology specification |
Current status
For those bar code symbologies that are not published as ISO standards, you can visit AIM (http://www.aimglobal.org) to find the specification.
| Linear | Matrix | Stacked/Packet | Composite |
| Code 128 | Aztec Code | Code 16K | EAN.UCC Composite |
| Code 39 | QR Code | Code 49 | Aztec Mesas |
| Code 93 | Code One | Codablock F | |
| Code 93i | Data Matrix | SuperCode | |
| Codabar | Dot Code A | Micro PDF 417 | |
| Channel Code | MaxiCode | PDF 417 | |
| Interleaved 2 of 5 | |||
| Posicode | |||
| Reduced Space Symbology | |||
| Telepen |
Symbology standards are also available from other organizations. For example, the U.P.C. and EAN symbologies are available from UCC and EAN. Most proprietary symbologies are only available from their respective inventors.
What is a Symbology Standard?
A symbology specifications give all the details necessary to print or scan a barcode. The documents range from 8 pages to 120 pages, so you can see that there is a lot of information needed to create a barcode.
Looking at a standard from a very simplistic level, it must contain:
- A definition of the width of the bars and the spaces.
- A method to define each character that is encodable (whether numeric only or full ASCII).
- The start and stop characters
- Any check character support built in
- Any free space needed around the symbology to allow for a clean decode
From these basic definitions, it then gets to be complicated as error correction becomes a factor and as we start to talk about non-linear symbologies. With some of the two dimensional symbologies allowing the encodation of several kilobytes of data, on a symbol that may be several square inches in size, it become important to fully define the “rules” for a symbology.
Posted with Steve Halliday permission, president of High Tech Aid.