UPC-A is used for article bar-coding. It is used in the United States for marking of products in retail applications (similar to EAN). The article number is maintained by UCC and identifies manufacturer and product uniquely. The code (11 digits + 1 check digit) is built from one system-digit, 5 digits manufacturer code and 5 digits product code. The check digit is calculated automatically.
Valid characters: "0".."9"