"Partner Discount" Item does not appear in any item list, global search. Where is it?

I do now believe I have lost my mind...

I have a customer who regularly used a line item on sales orders called "Partner Discount" and it works (mostly) as expected.  The customer had a question regarding how it is set up so I tried to bring the item up through Global Search and got No Results Found.  I went into items -> List and filtered on Discount items (and showing Inactives).  I see the 4 other Discount items they use but not "Partner Discount".

I have a search that retrieves only line items where the item Name is Partner Discount so I edited that and had it also return the Internal ID of that item and it gives me "-6".  So I create a saved item search to only display an item with internal ID = -6.  No results found.