What is Code 11?
Code 11 is a numeric linear barcode developed by Intermec in 1977 for labelling telecommunications equipment. It encodes digits 0-9 plus the dash character, and carries one or two built-in check characters (C and, for longer data, K) that catch misreads. It survives in telecom inventory, equipment racks and some legacy label formats where the installed scanners were configured for it.
Common Uses for Code 11
- Telecom equipment and rack unit labels
- Legacy inventory systems configured for Code 11
- Component and serial labels where dash-separated numbers are used
- Applications that specify USD-8 symbology
Code 11 check characters (C and K)
Code 11 is not fully self-checking, so it appends check characters: a single C check for short strings, and for data of ten characters or more a second K check as well. The checks are weighted modular sums over the data digits and dashes. Scanners verify them on every read, which keeps numeric-only labels reliable even when printed small - and the generator fills them in for you, so any digits-and-dash string you enter produces a complete code.
Code 11 vs Interleaved 2 of 5
Both are numeric-only codes that appear in legacy equipment labelling. Interleaved 2 of 5 is denser for long digit strings but must contain an even number of digits and carries no dash. Code 11 handles dash-separated identifiers and adds its own check characters, at the cost of lower density. Match the symbology to what your scanner fleet and backend expect rather than choosing on density alone.
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