When you setup parts/accessories for a product, the setting 'Included w/Product' determines on which forms the items will be shown.
If you want the items to be shown as Items Requested on the New Return or Quick Return forms, select YES for 'Included w/Product'. These forms show parts/accessories that are normally included with the product that the customer is requesting to be replaced. These items will also be shown on New Parts Request and Quick Parts Request forms.
If you want the items to only be shown on New Parts Request and Quick Parts Request forms, then select NO for 'Included w/Product'. These forms show all parts/accessories, not just those that are included with the product.