There are three different types of coupon identification codes; a global coupon identifier, a prefix for coupons denominated in Euro and a third for coupons issued in Sterling (GBP).

A Global Document Type Identifier or GDTI is the GS1 Identification Key for a document type which may be combined with an optional, alpha-numeric serial number.

The CPID is the GS1 Identification Key used to identify a Component or Part. Each component part that is different from another is allocated a separate, unique CPID.