The Korean Postal barcode is Korea Post's barcode for the 6-digit postal code, followed by a check digit.

What it holds
Characters	Digits only.
Length	6 digits, or 7 with the check digit.
Check digit	Always there. Type it or leave it out: Labeljoy works it out, and if you typed one it checks that it's right.
Readable text	The 7 digits, 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 7th digit you typed isn't the right check digit.
Invalid number of characters in the input data.	Fewer than 6 digits.
Input data too long.	More than 7 digits.
Numeric only data expected.	The value has something other than digits.