When you delete a single file or folder, the delete confirmation dialog displays basic details (metadata) like the file or folder name, date created, file type, and date modified by default, but will vary with each file type.
A prop: value indicates a individual property or metadata within the Windows Property System that can be set on files/folders. You can customize the prop: value for the delete confirmation dialog to show any file and folder details you like in the prompt. The details you set to show in the prompt will only show if the property or metadata is available for the deleted file or folder.
This tutorial will show you how to customize the delete confirmation dialog to show any file and folder details you want in the prompt for all users in Vista, Windows 7, Windows 8, and Windows 10.