While you are reviewing an item, scroll down to the 
Substitutes button.
Tap the Substitute button to display a list of substitute items for the item.
When you look up an item, you can view the substitute items that are assigned to that item by following these steps:
While you are reviewing an item, scroll down to the Substitutes button.
Tap the Substitute button to display a list of substitute items for the item.
You can tap a substitute item to review the details for that item.
Tap Back to return to the item screen.
