Creating Role Specific Drupal Registration Forms
Overview
Sometimes Drupal installations need to have specific tasks performed upon the registration of different types of users. For example, most Drupal sites have multiple user roles, with these roles being applied to accounts by administrators, post account creation. An example of this would be a site that connects people with service providers for a given service. Service providers must provided with the role Service Provider
to be able to act as a service provider on the site.