When you open applications, from the built-in memory or the Expansion Card, they save data onto your device.
This data is used by the application when active, and normally, will be deleted when you delete the application itself.
Each and every application on your device has to have a unique Creator ID.
Applications, in general, use this Creator ID to save their data.
When you choose to delete an application, the system finds and removes items that share the same Creator ID with this application.
However, some applications, intentionally or by a programming error, save items under a different Creator ID than their own; these items will remain on your device, occupying your precious handheld memory for good.
Leftover files and preferences survive hard-resets; the HotSync Manager restores them one by one to your device.
Cleanup will help you get rid of them once and for all.
To monitor new applications and completely uninstall them, use Uninstall Manager; to delete old leftovers that already inhabit your device, use Cleanup.
Backup (and Restore) the Preferences resource before deleting it.
Search for the orphaned item's (File or Preferences) Creator ID to determine if it's really orphaned.
Exclude applications from the Search Process for a faster search.
Export the Search Results into a Memo Pad record.
Compare orphan items with the Signature File to easily identify "unidentifiable" items.