PDF 417 holds a lot of data in a block of rows: it's on ID cards and driving licences, boarding passes and shipping documents. Each row starts and ends with the same patterns, and error correction lets it read with part of it damaged.

Standard

Truncated

Modes
Standard	The usual PDF 417.
Truncated	Narrower: the right-hand patterns are cut down to a single bar. For a clean, well-printed label where the space is short.

What it holds
Characters	Letters, digits and symbols, and the accented letters of Western European languages - é, ü, ñ and the like. The euro sign, other alphabets and emoji don't fit: use a QR Code for those.
Length	With Automatic error correction, up to 2,528 digits, 1,724 letters, or about 1,000 characters of mixed text. More error correction holds less: at level 8, about half that.
Readable text	None.

Settings
Columns	How many columns of data each row holds: Automatic columns, or from 1 to 20. More columns make a wider, shorter barcode. With a number that would need more than 90 rows, Labeljoy adds a column.
Error correction	Automatic error correction picks a level from the length of the value, as the standard recommends; 1 to 8 choose one - each level doubles the error correction. With Truncated it's greyed out and set to Automatic error correction.
Encoding	Standard or HIBC: see GS1 and HIBC data.

The rows are three modules high, the standard's minimum. Turn Keep aspect ratio off to stretch the barcode to the element instead.

Characters you can't type. With Encoding set to Standard, a tilde followed by three digits is the character with that code - ~013 is a carriage return - and ~~ is a tilde.

The rest of the settings - quiet zone, color - are in the Barcode section.

What goes wrong
Input data too long.	The value doesn't fit even the largest PDF 417 with that Error correction - or, in HIBC, it's longer than 110 characters.
Input data too long for specified number of columns.	The value needs more columns than you chose: choose more, or Automatic columns.
Only Latin-1 characters, the letters of Western European languages, fit in this barcode.	The value has a character PDF 417 can't hold - a euro sign, another alphabet, an emoji.
Invalid data in input.	HIBC: the value has a character HIBC doesn't take - see GS1 and HIBC data.