The Global Trade Item Number (GTIN) is the globally unique GS1 System identification number for products and services. A Global Trade Item Number may be 8, 12, 13, or 14 digits in length, represented as GTIN-8, GTIN-12, GTIN-13, and GTIN-14 respectively.

• UPC - Used by general retailing in the U.S.

• EAN - Used by retailing globally

• ISBN-13 - Becoming the standard product identifier for books

At this time, "GTIN Format" means expressing any of the above identifiers in 14 digits by prefixing them with zeros. This number is correctly called "GTIN-14" but is widely referred to simply as "The GTIN".

GTIN is the item identifier for transactions in the global supply chain, such as:

• Product Data (Metadata)        Receiving

• Ordering                                Invoicing

GTIN is not a product identifier for marking individual items.

GTINs appear today on cartons (cases) in general retailing; they are especially noticeable in grocery stores.

At the item level, GTINs are built by expressing the ISBN-13 (or any other EAN) as a 14-digit number by prefixing it with zero:

ISBN-13:  978-0-940016-73-6

GTIN:       09780940016736

Prefixes '1' - '8' have significance as packaging level indicators but are not yet defined for the book industry.

Adopting the 14-digit GTIN standard aligns the book industry with national and global supply chain practices.

GTIN would enable participation in global product data synchronization (data distribution):

• The GTIN is the standard identifier for Global Data Synchronization (GDS)

• Data synchronization means establishing sources of standardized product data: (1) data with known, validated attributes (properties); (2) data that may be used by all participants in  a supply chain.

GTIN would permit the book supply chain to use package level choice when ordering:

• The leading digit of the GTIN permits specifying packaging level (unit, case, pallet)

• Packaging level is a major factor in general retail supply chains (case pack handling)

BISG endorses only a 14-digit field length for electronic communications

• Communications practices are outward facing - they affect trading partners

• A single standard for electronic communication is essential to minimize confusion and duplicate provisions for electronic communications

BISG recommends a product identifier field of at least 14-digits in all databases:

• If a system is SKU-based, then cross reference tables and displays (screens and hard copy) should comply