For registrations, one registration form completion equals one username and one registration record.  By registering with different email addresses, 2 different constituent/supporter records and ids will be created.  Do not merge the records, or the user will not be able to log in properly. Each registrant must have a unique email address. If multiple registrants register with the same email address, unexpected behaviors may occur. These unexpected behaviors include, but are not limited to the following:
  • All registrants with the same email address will be given the username of the registrant who signed up most recently. 
  • Password reset emails will only be sent for the username of the most recently registered participant
To deter this behavior:
  1. The participant should register for the event with Username A and the Email address A
  2. The participant should not use autofill.  He or she should register for the event again, but should use Username B and Email address B

Note: some email providers ignore a period in the email address. For example, if you have email address, you could register as registrant A, and then for registrant B. Again, you will not want to merge these records. To Gmail, these are the same exact email address, but Sphere considers them unique.