### UPC-E

UPC-E Structure (From left to right)
Start guard bars, always with a pattern bar+space+bar.
Left half, five digits calculated from the equivalent UPC number.
Check digit.
Stop guard bars, always with a pattern bar+space+bar.

UPC-E (Universal Product Code-E) is fixed in length and is a compressed six-digit code used for marking small packages including magazines and paperback books. The printed value of the UPC-E code is a twelve-digit code. UPC-E symbols are UPC-A symbols that have been zero suppressed (i.e. consecutive zeros are not included in the symbol). The nominal height for the UPC-E bar code is one inch. The reduced size is 80% of the nominal size.

The left guard bar is encoded with 101, and the right guard bar is encoded with 010101.