When migrating from another forum system (in my case SMF -> phpbb3 -> XF), I believe it stores the original and new post id's in tables? So for htaccess 301 redirects from old links we can use regex to shift to the new format and XF will translate to the XF id of the actual post correct? If that is so, does it matter whether I create new categories and forums before the migration (that will be staying and included in addition to the migrated categories/forums), or is it advisable to add new content only post-migration? If no content at all is in the XF forum then the id's would be identical and make redirection easier? edit: ugh this should go in the import forum.