Use Username instead of Email for identity in Asp.net mvc5

Question

Whenever I create a new application with visual studio 2013 express for web and using the individual accounts authentication and i hit the register button I notice that it i

Answer 1

In order to make email as non unique:

Configure below in IdentityConfig

manager.UserValidator = new UserValidator(manager)
            {
                AllowOnlyAlphanumericUserNames = false,
                RequireUniqueEmail = false                
            };