Name must not be empty and must not exceed 60 characters. Referral code must be unique, exactly 14 characters and on the form "STAR-XXXX-XXXX".
Email is optional, and will not be given out to anyone. Length of email address must not exceed 100 characters. Entries will expire after 100 days, and if you enter a valid email address you will be automatically notified when this happens.
If you don't know your referral code, you can find it here (which will, of course, require you to log in). For more info on CIG's referral program, see this page.