(aka USS Code 39, Code 3/9, Code 3 of 9, USD-3, Alpha39) The first alpha-numeric symbology that originally encoded 39 characters (now 43) including uppercase letters (A - Z), digits (0 - 9) and a few special characters like the $ sign. The entire ASCII character set can be encoded using Code 39’s Full ASCII mode. The bar code does not contain a check digit but is considered self-checking because a single erroneously decoded bar can not generate another valid character. The code has very low data density compared to other 1D codes which does not make it feasible for small space applications.
