The customer should get the sku of the product in the catalog, cart and checkout process to avoid missunderstanding as this standard sku is communicated in the price list, the custom options has no price difference as it handles technical features like country specific cables or different frequencies.
For the import to the erp system we need the custom option sku as it definies the product variant in the erp system.
product sku ABC
custom option colour
blue sku ABC_00
red sku ABC_01
The object modell of the saved product should have the standard sku (ABC) and in the custom options the variant sku (ABC_01).
In our ERP System Navision the item (sku) has a standard number and optional variant codes.
Questioin: Which file / function defines the sku and the custom option sku?