Logistic shelf and master cartons should be identified with a GTIN-14 identifier. In most environments, these cartons are not read by point-of-sale scanners and do not carry a UPC barcode symbol. An ITF-14 barcode encodes the GTIN-14 information. The GTIN-14 data structure is comprised of four components:
- Indicator – This denotes the level of packaging for a particular carton. This one-digit prefix can range from 0 to 8.
- GS1 Company Prefix – Vendors must obtain a GS1 Company Prefix directly from GS1 to uniquely identify their company. Depending on the number of items a company needs to identify, a GS1 Company Prefix may be 7 to 10 digits in length.
- Item Reference– References the same product number used for the item level GTIN (GTIN-8, GTIN-12, GTIN-13) when a carton is made up of the same item. For cartons that contain an assortment of items a new product number is assigned.
- Check Digit – The last digit of GTIN-14 is a calculated check digit. Using a MOD10 check digit algorithm, the calculated check digit prevents substitution errors. An online check digit calculator is available at https://www.barcode.graphics/check-digit-calculator/.