Database directory issue

Our app has been rejected with this indications by Apple:

"Please verify that only the content that the user creates using your app, e.g., documents, new files, edits, etc. is backed up by iCloud as required by the iOS Data Storage Guidelines. Also, check that any temporary files used by your app are only stored in the /tmp directory; please remember to remove or delete the files stored in this location when it is determined they are no longer needed.

Data that can be recreated but must persist for proper functioning of your app - or because users expect it to be available for offline use - should be marked with the "do not back up" attribute. For NSURL objects, add the NSURLIsExcludedFromBackupKey attribute to prevent the corresponding file from being backed up. For CFURLRef objects, use the corresponding kCRUFLIsExcludedFromBackupKey attribute."

We are surprised because our database is in the Library root folder (not in Caches), and no content is stored in the Documents folder. So, why they quote iCloud and Data Storage GuideLines related to Documents folder?

Many thanks for your help.