Referral Code Blacklist
Referral codes are a short string of alphanumeric characters at the end of a referral link. For example, the referral code for the PURL http://fbuy.me/EzcW is EzcW.
You can manage the blacklist of referral codes from Settings > Configurations > Referral Code Blacklist. From here, you can add new referral codes to the blacklist or remove existing ones.