Codabar (NW-7)
Blood banks, libraries, and parts of the FedEx network still read Codabar, a symbology Monarch Marking Systems released in 1972 and catalogued elsewhere as NW-7 or Code 2 of 7. Its four start and stop characters, designated A, B, C, and D, can be assigned meaning by the issuing system, so an identical numeric payload conveys different context depending on which pair frames it. The data character set covers the digits 0 through 9 and the symbols - $ : / . and +, with no alphabetic capability. Encoding is self-checking, and the design predates the check-digit conventions of later linear codes. A 0.19 mm X-dimension and ten-module quiet zones are typical. Codabar is not a GS1 carrier, and its persistence owes more to installed-base inertia in regulated archives than to technical merit.
An early self-checking barcode symbology still used in blood banking, library systems, and some FedEx applications. Codabar uses four start/stop characters (A, B, C, D) that convey additional context about the encoded data's purpose.
Codabar (NW-7)
1D LinearRelated Guides
Codabar: The Legacy Barcode in Blood Banks & Libraries
Codabar's encoding scheme, four start/stop characters (A-D), ISBT 128 successor in blood banking, and where it's still used today.
Blood Bank Barcodes: ISBT 128 & Transfusion Safety
ISBT 128 barcode standard for blood products — donation identification, component labeling, and the transition from Codabar to ISBT 128.