Editing PDF417 (section)

=== Encoding ===

Of the 929 available code words, 900 are used for data, and 29 for special functions, such as shifting between major modes. The three major modes encode different types of data in different ways, and can be mixed as necessary within a single bar code:

* ''Byte'': each group of 5 code words represents 6 bytes. (Because 900<sup>5</sup> &gt; 256<sup>6</sup>.) Additional bytes are encoded one per code word.
* ''Numeric'': ''n'' digits are encoded in {{floor|''n''/3}}+1 code words, up to a maximum of 44 digits in 15 code words.
* ''Text'': Each code word represents two base-30 digits, which are used by a system of four submodes to represent the printable ASCII characters (plus [[Carriage Return|CR]], [[Line Feed|LF]] and [[Horizontal Tab|HT]]):
** Uppercase: A&ndash;Z, [[Space (punctuation)|SP]], Change to lowercase, Change to mixed, Interpret next digit as punctuation
** Lowercase: a&ndash;z, SP, Interpret next digit as uppercase, Change to mixed, Interpret next digit as punctuation
** Mixed: 0&ndash;9, &, CR, HT, comma, :, #, -, period, $, /, +, %, *, =, ^, Change to punctuation, SP, Change to lowercase, Change to uppercase, Interpret next digit as punctuation
** Punctuation: ;, <, >, @, [, \, ], _, `, ~, !, CR, HT, comma, :, LF, -, period, $, /, ", |, *, (, ), ?, {, }, ', Change to uppercase