Deutsche Post, the German postal service, prints two barcodes on parcels and letters, both built on Interleaved 2 of 5: the Identcode, which identifies a shipment, and the Leitcode, which routes it to its address.

Identcode

Leitcode

Modes
Identcode	11 digits: the mail center (2), the customer (3) and the delivery number (6).
Leitcode	13 digits: the postcode (5), the street (3), the house number (3) and the product (2).

What it holds
Characters	Digits only.
Check digit	Always there. Type it or leave it out: Labeljoy works it out, and if you typed one - a 12th or 14th digit - it checks that it's right.
Readable text	The digits with the check digit, under or over the bars.

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

What goes wrong
Invalid check digit.	The last digit you typed isn't the right check digit - often a sign of a mistyped number.
Invalid number of characters in the input data.	Too few digits: fewer than 11 (Identcode) or 13 (Leitcode).
Input data too long.	More than 12 digits (Identcode) or 14 (Leitcode).
Numeric only data expected.	The value has something other than digits.