Product identifiers are used to define and distinguish products in the global marketplace. Understanding the product identifiers that you can use with Skublox is an integral part of the order fulfillment process. Skublox supports the following product identifiers:
| IDENTIFIER | DESCRIPTION |
| SKU | A unique code assigned to a product. SKUs are used as the primary product identifier. Typically, merchants create their code as the product SKU. |
| UPC | A type of code that is printed on the retail product packaging to help identify a particular item. |
| Shadow SKU | A type of virtual product that “shadows” another product. Its inventory is linked to an actual stock SKU, but it can have its alternate product profile. |
| Replacement SKU | This is used for interchangeable items and will enable Skublox to recognize the replacement SKU. |
| Alias | An alternative reference for a given product. Adding an alias to a product makes it easier to find it in the system and in the warehouse. |
