Optional Sales Order Features > Item Replacement
  PPT
Item Replacement
When you take a customer order, requested items may not be available for customer delivery. You can substitute the requested item with one of the following:
Replacement items, which replace the requested item with an equivalent item
Up-sell items, which replace the requested item with an item of higher value
In addition, you can sell:
Cross-sell items, which are not replacement items for the requested items but sold in addition to the requested item to increase revenue or as a promotion for an item.