USA standard, for items sold to the public. UPC-A contains numeric data only (i.e. GTIN-12) and encodes a 12-digits number. The first one is the system number character, the next 5 digits are the supplier ID, the next 5 digits are the product number, and the last one, the required checksum character. You do not need to specify the checksum digit as BarDIMM Pro and BarDIMM Box recalculate it.
A digit is described by 2 bars and 2 spaces and its width is calculated as 7 thin bars.
The number character is printed as text on the left side or the bar code and the checksum on the right side.
The system number can have the following values:
0 or 7: Regular UPC codes
2: Random weight items
3: National Drug Code and National Health Related Items Code
4: For use without code format restriction and with checksum for non-food items
5: For use on coupons
1,6,8,9: Reserved