$output .= '<p>' . t('The HTTP Basic Authentication module supplies an <a href="http://en.wikipedia.org/wiki/Basic_access_authentication">HTTP Basic authentication</a> provider for web service requests. This authentication provider authenticates requests using the HTTP Basic Authentication username and password, as an alternative to using Drupal\'s standard cookie-based authentication system. It is only useful if your site provides web services configured to use this type of authentication (for instance, the <a href=":rest_help">RESTful Web Services module</a>). For more information, see the <a href=":hba_do">online documentation for the HTTP Basic Authentication module</a>.', array(':hba_do' => 'https://www.drupal.org/documentation/modules/basic_auth', ':rest_help' => (\Drupal::moduleHandler()->moduleExists('rest')) ? \Drupal::url('help.page', array('name' => 'rest')) : '#')) . '</p>';