A referral code is unique to each member. This code is used to determine which member referred which referral so they get proper credit.
By default, referral codes are generated automatically based on the member's name. On any page of the Program Editor you may edit the configuration of referral codes by selecting the gear icon in the top right corner and then selecting "Referral Code".
You can choose to issue the member a randomly generated referral code, a personalized code based off of their first name, or a personalized code based off their first name including a set prefix.
A few things to note...
Codes have to be unique across your account as they are also in the Member's referral URL.
All codes can only include letters and numbers.
Codes are required to be at least 6 characters and up to 15 characters long (including an optional 3 character prefix).
Codes are not case sensitive.
You can edit a member's code yourself by going to the member's profile and selecting 'Edit'. Referral codes can also be edited through the API.
When importing Members you can set their referral code as long as it satisfies the above rules.
If you decide to create your own or edit an existing referral code, the generation options are not applied.