Codablock F is a stack of Code 128 rows, from 2 to 44 of them, each with a number that tells the scanner where it belongs. It holds a long value in a block much narrower than one Code 128 would be.

What it holds
Characters	Every letter, digit and symbol on the keyboard, and the accented letters of Western European languages - é, ü, ñ and the like. The euro sign and other alphabets don't fit: use a QR Code for those.
Length	Up to 5,452 digits or 2,726 other characters - an accented letter counts as two.
Check digit	A check character in each row, and two for the whole barcode, worked out by Labeljoy.
Readable text	None.

There's nothing to set: Labeljoy chooses the number of rows and how many characters go in each, to keep the block about as tall as it is wide. A short value still gets two rows.

Characters you can't type. 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 44 rows.
Only Latin-1 characters, the letters of Western European languages, fit in this barcode.	The value has a character Codablock F can't hold - a euro sign, another alphabet, an emoji.