Telepen
A British library symbology encoding full ASCII at one character per module pair, still used in UK university and legal libraries.
Telepen Specification
| Character set | Full ASCII, including control characters |
| Data length | Variable; constant width per character |
| Check digit | None mandatory (structure is self-checking by design) |
| Density | Moderate; every character occupies the same 4 modules |
| Module width (X-dimension) | 0.19-0.50 mm typical |
| Print ratio | Fixed alternating pattern (not two-width) |
| Magnification | Not fixed; scales with X-dimension |
| Quiet zone | 10X on each side |
| Standard | SB Electronic Systems / Telepen Ltd proprietary |
| Origin | SB Electronic Systems (UK), 1972 |
Not generated by barcodegen.net
Telepen is documented here for completeness, but our free generator does not produce this symbology. The closest supported format is Code 128.
What Is Telepen?
Telepen (developed by SB Electronic Systems, UK, 1972) is unusual: it encodes each character in a fixed 4-module pattern of alternating bars and spaces, giving constant symbol width per character and full ASCII without code-set switching. It was designed for library circulation, where compact alphanumeric item IDs needed reliable scanning from the wands of the era.
It remains a live standard in UK libraries — many university and legal libraries (and their integrated library systems) still use Telepen on book labels and borrower cards — and Telepen Ltd still licenses the encoding. Outside the library world it is unknown. New library deployments weigh Code 39 or QR codes against the installed Telepen reader base.
Common Applications
- UK university and legal library circulation
- Library borrower card identification
Related Barcode Types
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.
The classic self-checking alphanumeric barcode: 43 characters, simple structure, still everywhere in industry.