This table explains the data between Trade Runner and Shopify
|TradeRunner Data||Shopify Data||Trade Me Data|
|SKU||This is the Shopify product ID - a number generated by Shopify when you create a product|
|Retailer Reference||This is the Shopify Variant ID - a number generated by Shopify when you create a product|
This is important information to note when creating Product Groups in Trade Runner. Product Groups require the SKU we have in Trade Runner not the SKU you may have used on Shopify.
The actual field in Shopify called SKU is not a mandatory field nor a required field, so it is not a reliable field in Shopify. Our App must have a SKU as part of the Trade Me listing requirement and because we cannot rely on Shopify providing that data via the SKU field we use the Shopify Product ID to create a SKU in Trade Runner This Trade Runner SKU cannot be edited and it must be used when creating groups, promotions etc.