Use the Substitute Code field on the Settings tab of the Advanced Product Settings to specify the method by which to perform product substitutions for a selected product. You have the following options:
No Substitution - Do not substitute for the selected product.
Comparable Product - If insufficient quantity exists to satisfy an order for the selected product, substitute the product specified at the Substitute Product field. The system does not split line items in this case. The system derives the product description, the selling price, and the costs from the substitute product and posts sales analysis information to the substitute product.
Always Substitute - Whenever this product appears on an order, always ship the substitute product specified at the Substitute Product field. The system derives the product description, the selling price, and the costs from the substitute product and posts sales analysis information to the substitute product.