Each GS1 DataBar Expanded symbol encodes up to 74 numeric or 41 alphanumeric characters. Because it is a variable-length symbology, the width of a symbol can vary from 53 to 543 modules.

The symbol comprises the following elements:

• Left guard pattern (narrow space, narrow bar)

• Check digit

• One to eleven triplet sequences that consist of a finder pattern followed by two symbol characters (unless there is an odd number of characters, in which case the last triplet sequence has two elements instead of three)

• Right guard pattern (narrow bar, narrow space)

The first digit is a flag that indicates whether the barcode is part of a composite barcode. The data itself is split into groups that contain two data characters and one finder pattern. Each data character is 17 modules wide, using four bars and four spaces. The finder patterns separating the groups are 15 modules wide, using five bars and spaces total.

A quiet zone is not required.

This symbology supports the following characters:

• All numeric digits (0-9)

• All uppercase and lowercase letters (A-Z and a-z)

• Special function character (FNC1)

• Special characters:

  • Exclamation point (!)

  • Quotation marks (")

  • Percent sign (%)

  • Ampersand (&)

  • Apostrophe (')

  • Opening parenthesis (()

  • Closing parenthesis ())

  • Asterisk (*)

  • Plus sign (+)

  • Comma (,)

  • Hyphen (-)

  • Period (.)

  • Slash mark (/)

  • Colon (:)

  • Semicolon (;)

  • Left angle bracket (<)

  • Equal sign (=)

  • Right angle bracket (>)

  • Question mark (?)

  • Underscore (_)

  • Space character

GS1 DataBar Expanded contains a check digit that uses the modulo 211 (mod 211) algorithm for error correction.