I looked at some coupons I clipped and they don’t have a 999 code.
Where did you get that list anyways?
Sorry, I should have posted the source...
en.wikipedia.org/wiki/List_of_GS1_country_codes
Some internal coupons are using their own proprietary codes. That way they can control the redemption to the stores they choose.
When you read the regulations, there are umpteen options. I was even set up with my own UPC for Hydroponic Lettuce back when I was growing it in the greenhouse. Then you have to be input into the stores computer so their scanners will recognize it.