The product identifier is the key that correlates all product data from different types.
All four :doc:`data types <data-types>` specify the product key by using the element
Model Product and Variations
The model product (see :ref:`product`) must always have its own unique key, regardless of whether it has any variations or not.
If the product has any variations, each variation is obligated to have its own unique product key.
A variation product cannot be redefined to later map to a different model product.
No check will be done to identify duplicate (and possibly conflicting) product identities. It is the merchant's responsibility to maintain data consistency in regards of product identities.
For the product data types :doc:`availability <api/availability>`, :doc:`media <api/media>` and :doc:`price <api/price>`, data associated with the model product's key is discarded if the product has variations.
The Product Data Type
The :doc:`product data type <api/product>` has encapsulated the
<id> element inside an
<identity> <id>main_product_key</id> <gtin>global_trade_item_number</gtin> <mpn>manufacturer_part_number</mpn> <sku>stock_keeping_unit</sku> </identity>
id-element is always mandatory.
The other elements,
sku are product data that is not used for identification during processing, but are persisted if provided.
Except for the
id-element, the identifiers are primarily optional. However, certain categories require one or more of them, which will be enforced during processing.
Note that product id:s are not case sensitive! For example, the following id:s are all considered equal:
Product_A product_a PRODUCT_A pRoDuCt_A
Valid Identity Characters
A valid product key is 1–40 characters long, and only accepts certain characters.
The following characters are allowed in an identity token:
- / (slash)
- - (hyphen)
- _ (underscore)
If specified, the element
gtin must be exactly either 8, 12, 13 or 14 digits long. For reference, see gtin.info.
The restrictions are more lenient for the elements
sku. If specified, 1–50 characters of any kind is permitted.