If you deleted an item (product or material variant) in Katana, related line items on sales orders, purchase orders, stock adjustments, and stock transfers are displayed as crossed out (strikethrough).

Deleted items cannot be restored in Katana. If you want to restore an item, you need to create a new item with the same name and attributes. On orders, you can delete the line item that has been crossed out and replace it a newly created item.