Deleting report catalog objects permanently
When you delete reports, folders, and report books and their folders, they are removed from your view of the report catalog but they are not purged from memory until they are checked in. You can thus use the Undo Check-out option on a folder to un-delete reports within it.
To delete objects permanently, without checking in the parent folder, use the Delete Permanently option. Right-click the object in the report catalog and select Delete Permanently.