The Code 39 character set includes the digits 0-9, the letters A-Z (upper case only), and the following symbols: space, minus (-), plus (+), period (.), dollar sign ($), slash (/), and percent (%). A special start/stop character is placed at the beginning and end of each barcode. The barcode may be of any length, although more than 25 characters really begins to push the bounds. Each character consists of 9 elements: 5 bars and 4 spaces. Each character includes 3 wide and 6 narrow elements. Characters are separated by an inter-character gap which is the same width as a narrow bar.
Uses:
Code 39 is widely used in many industries and is the standard for many government barcode specifications, including the U.S. Department of Defense.