Plessey
The original 1971 hex-capable library and retail symbology from Plessey Company — the direct ancestor of MSI Plessey.
Plessey Specification
| Character set | Hexadecimal: 0-9 and A-F |
| Data length | Variable |
| Check digit | Cyclic redundancy check sequence (not a simple check digit) |
| Density | Low to moderate — 8 modules per character plus check trailer |
| Module width (X-dimension) | 0.19-0.50 mm typical |
| Print ratio | Variable-width bars (module-based, not two-width) |
| Magnification | Not fixed; scales with X-dimension |
| Quiet zone | 10X on each side |
| Standard | Plessey Company proprietary (1971); no ISO standard |
| Origin | Plessey Company (UK), 1971 |
Not generated by barcodegen.net
Plessey is documented here for completeness, but our free generator does not produce this symbology. The closest supported format is MSI Plessey (Mod 10).
What Is Plessey?
Plessey was developed by the Plessey Company (UK) in 1971 and is notable for encoding hexadecimal digits (0-9 and A-F) — one of the few early symbologies with a non-decimal character set. Each character is eight modules wide with a distinctive bar pattern, plus a lengthy trailing check sequence. It found early use in library circulation systems and UK retail pilot projects.
MSI Plessey (modified by Image Data Inc.) refined it in 1972 with simpler Mod 10/11 check digits and digits-only encoding, becoming the variant that actually survived in warehouses. Original Plessey is now rare outside old library installations; scanners with Plessey support are increasingly scarce. For any new inventory application, MSI Plessey or Code 128 is the practical choice.
Common Applications
- Historic library circulation systems
- Early UK retail pilots (historical)
Related Barcode Types
A digits-only inventory barcode with a single Mod 10 check digit, descended from the Plessey code.
A high-density, variable-length linear barcode that encodes all 128 ASCII characters, and the backbone symbology of modern logistics.
A self-checking numeric barcode with start/stop letters, historically used by libraries and blood banks.