Drupal - Open Source CMS. ACL. Private forums in Drupal: Forum Access vs. Taxonomy Access vs. Taxonomy Access Control Lite. Introduction Most people who use forum systems such as vBulletin or PHPBB are used to having lots of extra features that Drupal core's forums don't contain by default, including private messages, smilies, and BBcode.
While all of those are available as contributed modules, there are two "must-have" forum features that are a bit trickier, since they deal with access control: private forums, and forum moderators. Drupal core tends to have an "all or nothing" approach to these issues.