Rules Forms Support allows users to manipulate forms when a form is built, during validation, or when a form submitted. Once events are activated for a form, users can define rules to accomplish tasks like validating form element values, setting form errors, redirecting users, or setting form titles. It was originally developed for and shipped with Rules 1 (Drupal 6), but since the release of Rules 2 (Drupal 7), the Rules Forms Support project has been moved to a separate, standalone module.