Codabar is a variable length symbology which encodes a character set of 16 letters ( 0-9, -, $, :, /, +). It is dubbed as NW-7 in Japan. You may choose one of these four start/stop characters in your symbol: A, B, C and D. If you do not specify the start/stop characters, Monterey Barcode Creator uses A and B as the start/stop characters, respectively. No check digit is required.