When trying to register an organisation (e.g. a club) or a facility (e.g. a stadium), Member Association may encounter a 409 error, meaning that potential duplicates have been detected. If they are sure that this was a false positive (not a true duplicate), they may use a "force" flag to override this mechanism and register an organisation/facility.
Note that the duplicate detection is limited to organisation & facilities registered withing the same Member Associations.
If you are interested in the details on how the duplicate detection works, reach out to support.id@fifa.org and we will describe it for you.