Lexmark T656 Technical Reference Manual page 62

d Center guard bars, encoded as 01010.
e Last three message characters, encoded as right-hand characters.
f Check digit, encoded as right-hand character.
g Right-hand guard bars, or end sentinel, encoded as 101.
4
EAN-13 (including +2 and +5 variants)
EAN-13, based upon the UPC-A standard, was implemented by the International Article
Numbering Association (EAN) in Europe. The only difference between a UPC-A symbol and
an EAN-13 symbol is that the number system code is 2-digits long in EAN-13 as opposed to
one digit in UPC-A.
An EAN-13 bar code has the following physical structure:
a Left-hand guard bars, or start sentinel, encoded as 101.
b The second character of the number system code, encoded as described below.
c The five characters of the manufacturer code, encoded as described below.
d Center guard pattern, encoded as 01010.
e The five characters of the product code, encoded as right-hand characters, described
below.
f Check digit, encoded as a right-hand character, described below.
Composite bar codes
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