Codabar

Codabar barcodes are linear 1D barcodes that identify and track items requiring a serial number. They are self-scanning and easily produced on many printers, including dot code printers.

Codabar barcodes can encode 16 characters, including 10 numerical characters, four letter characters (A, B, C, D), and a limited number of special characters (–$:/.+).

Codabars are most commonly used to identify and track items, for example, in retail (labeling goods), healthcare (patient, blood, and specimen identification), libraries (labeling books), and logistics (labeling packages and shipments).

Codabar codes are still used today because of their ease of use and readability. However, some consider them outdated, as newer codes (such as Code 128 and the EAN barcode) can store much more data in a smaller space.

The guard pattern indicates where the barcode begins and ends. One of the letter characters (A, B, C, or D) forms the guard pattern of a Codabar as the first and last symbols.

Codabar is a variable-length barcode. This means it supports variable-length data using a limited character set and stop and start characters (A, B, C, D).

The number of symbols measures the length of data encoded in variable-length symbologies such as Codabar. The number of symbols corresponds to the number of digits in the code, plus the start and end symbols. (Example: the code “A2334253D” has a symbol count of 7 + 2 = 9.)

A checksum is a value that is calculated from a dataset to detect data changes or errors. There is no universally agreed standard checksum algorithm for Codabar. However, some industries, such as libraries, adopt their own checksum standards.

Codabars are made up of bars and spaces with two widths (narrow and wide). The ratio between narrow and wide widths is between 1:2.25 and 1:3. The ratio of narrow to wide bars in a Codabar can be selected within this range.

The main limitation with using Codabar is data capacity. It can only encode 16 characters including 10 numerical characters (0-9), four letter characters (A, B, C, D) and a limited set of special characters (–$:/.+). This makes the Codabar barcode unsuitable for encoding complex data.

Codabars also have a minimal tolerance for damage or distortion. Even minor damage can make data decoding difficult. A Codabar increases in length, the more data is required. This makes the labeling of smaller items challenging.