This is a add on for http://codecanyon.net/item/powerful-exchange-system/533068
This addon is for version 2
This Addon is to enable that only a single user may register per i.p. address to prevent users from cheating the system to earn the referral bonus.
Width this addon you got a document where i write.
How you can be sure no user can make more then one user and get alot more coins. And nobody can spam you with fake users