AutoCAD Inventor :: Proper Way To Add Substitute Items In Parts List On Drawing?

I have some hardware in my parts list drawings that has a substitute for each other.  So you can use one of either item in the list.  Per the ASME guidelines, those two parts share the same item number in the parts list.  So my question is there any way to tell those two parts they are substitute from each other and they come into the parts list sharing that same item number.  Right now i'm manually changing that item number in the parts list. But if you try to re-order those parts it's a nightmare cause it's still treating that other item as a seperate entity.