Anonymize your referral links
By default, affiliate referral links are "pretty links". This means that they're generated using the affiliate's first and last name. When this option is enabled, your affiliates are also (by default) able to customize their affiliate links on their end.
However, it may sometimes be preferable to have anonymized affiliate links consisting of a string of numbers and letters that cannot be modified by the affiliate.
To enable anonymized links, all you have to do is go to Settings > Program > Advanced.
Here you will find the option to toggle off the default referral codes.