NW-7 (Japan, Narrow and Wide), JIS X 0503 (Japan), Rationalized Codabar, USD-4, 2 of 7 code
Overview
Developed in 1972, Codabar is discrete symbology , commonly used by the US blood banks and photo labs. FedEx also uses a variation of Codabar for its Airbills.
Encoding
Codabar can encode the following 16 characters: < li>
6 special characters: -, $, :, /, .,+
Structure
Codabar has the following structure:
A start character - one of (A, B, C, or D).
Inter-character gap.
Encoded value.
A stop character - one of (A, B, C, or D).
Requirements
To ensure quality, the width of the inter-character gap should be equal to the width of the narrowest element (X). The minimum value of X is 7.5 mils. The wide-to narrow ration (N) must be between 2.0 and 3.0. N remains constant. If X is less than 20 mils, N must be greater than 2.2. The barcode height must be at least 15 percent of the barcode length or .25 inches. Use the greater of these measurements.
