Ghost is an advanced permissions export and import tool designed to speed up the import process during a migration to XenForo.
After doing a test import and correcting any problems found, Ghost will allow you to save an XML file with all your permissions saved.
When you finish your live import, simply import the XML file on your live board to have the corrected settings take effect.
Note: For each item wishing to be exported and imported Ghost requires the content ID's etc to be IDENTICAL between the test board and the live import in order to function correctly. If the content ID's change, the permissions could be applied incorrectly or not at all.