Enter capital letters, digits, spaces and - . $ / + % to get a Code 39 barcode. Lower-case letters are converted to capitals, since Code 39 doesn’t have them.
Code 39, also called Code 3 of 9, is one of the oldest barcode types and is still called for by many industrial, automotive and government specifications, as well as ID badges and older inventory systems. Each character is made of nine bars and spaces, three of them wide. Every barcode starts and ends with an asterisk, which the scanner uses to find it and doesn't include in what it reads.
It supports 43 characters: A–Z, 0–9, space, and - . $ / + %. It needs no check digit, though some specifications add an optional mod-43 check character; this generator does not add one. Code 39 is wider than Code 128 for the same text, so if you have a free choice, Code 128 usually fits better.