Glossary
System.ItemPathDisplay
The Windows shell property holding the user-friendly full path of an item; in the search index it is the path you quote for a file, share or mail item.
System.ItemPathDisplay is documented by Microsoft as the user-friendly display path of an item. For files and folders it always includes the extension and may be localised. Microsoft's examples include local paths, UNC paths such as \\server\share\… and mailbox paths.
In Windows.edb it is stored in a column named like 4447-System_ItemPathDisplay; in Windows.db it is a property row whose ColumnId maps to that name. It is the field that shows a file existed at a location, even after deletion. Related properties: Windows Search index properties explained.