About the Type E UPC

This is a work in progress...

All Type-E UPC codes are eight digits long, the first being the Number System Character (NSC) and the last being the check digit. The number system character is ALWAYS ZERO. The check digit is calculated from the digits in the Type-A UPC.

So, that leaves the transformation of the middle ten digits of the Type-A UPC into only six digits in a Type-E. That's kind of complicated. I might document it here some time.