UK Plessey is the original Plessey code, from which MSI Plessey came. It holds hexadecimal values - digits and the letters A to F - and is still found on library books and shop shelves in the United Kingdom.

What it holds
Characters	Digits and the capital letters A, B, C, D, E and F.
Length	Up to 65 characters.
Check digit	Always there: a check code worked out by Labeljoy and added to the bars. It isn't in the readable text.
Readable text	The value, under or over the bars.

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

What goes wrong
Invalid data in input.	The value has a character other than digits and A to F - lowercase a to f included: type them as capitals.
Input data too long.	More than 65 characters.