- SKU

+ The stock keeping unit (SKU) is a unique number assigned to a product by a retail store 
  to identify the price, product options, and manufacturer.
  
  valuable for Tracking Inventory

  SKUs are not universal, meaning that each retailer has its own set of SKUs for its merchandise. 
  https://www.thebalancesmb.com/what-is-a-sku-in-retail-terms-2890158