GS1 Identifiers (ID Keys and Attributes)
The GS1 Identification System provides two types of identifiers. The first or primary identifiers are called GS1 Keys like the Global Trade Item Number (GTIN) or Global Location Number (GLN). Beyond the Keys, the GS1 Identification System also provides Key "attributes" like Lot Numbers or Expiration Date.
- GS1 Keys identify trade items (GTIN), locations/trading parties (GLN), logistic units (SSCC), groupings of logistics units (GSIN) & (GINC), individual assets (GIAI), returnable assets (GRAI), service relationships (GSRN), document types (GDTI) and coupons (GCN)
- GS1 Keys are mandatory to complete the identification of something and make the connection to GS1 BarCodes systems (like retail Point-of-Sale), eCom business messages (like an Order or Invoice), or to GDSN provided information.
- GS1 Keys and attributes can be carried by GS1 BarCodes
- GS1 Keys and attributes (e.g serial numbers, lot numbers, measurements and dates) can be carrried by GS1 BarCodes
- GS1 Keys with serialisation can be carried by EPC tags
- Attributes never complete identification without a GS1 Key being present (e.g., a lot number is not sufficient and may not be unique without knowing the trade item it is associated with)
- Many GS1 Keys have a special digit at the end called a Check Digit. This digit is calculated based on the preceeding numbers in the Key.