Code 39 or Code 39 Uss

Code 39 is also known as "USS Code 39", "Code 3 / 9", "Code 3 of 9", "USD-3", "Alpha39", "Type 39", "Code 93". It is a bar code symbology that can encode uppercase letters A through Z, numbers 0 to 9 and a handful of special characters such as the sign "$?. The bar code itself does not contain a check digit, in contrast for instance as with Code 128, but may be considered by some self-control, based on a misinterpretation bar alone can not generate another valid character.

Possibly the most serious drawback is its low Code 39 data density, since it requires more space to encode data in Code 39, for example, the code 128. This means that very small products can not be labeled with a bar code 39 and code base. However, the Code 39 is still widely used and can be decoded with virtually any barcode reader.

One advantage of Code 39 is that since there is no need to generate a check digit, can be easily integrated into existing printing system by adding a bar code font to the system or printer and then print the raw data in this source.

Code 39 (also known as 3 of 9 bar code) is a variable length, discrete, alphanumeric bar code. Its character set contains 43 significant characters: 0 - 9, AZ, -,., $, /, +,%, And "space?. Each character is composed of nine elements: five bars and four spaces. Three of the nine elements are wide (binary value 1), and six elements are narrow (binary value 0). However, the additional common character (*) is used to start and stop delimiters.

The name Code 39 derives from the fact that three of the nine elements of a codeword are wide elements and the remaining six are narrow. Code 39 was developed by Dr. David Allais and Ray Stevens of Intermec in 1974. He was later standardized as ANSI MH 10.8 M-1983 and MIL-STD-1189.