Redmine Comments plugin
This plugin improves private notes in Redmine issues. You can manage private notes visibility through roles and permissions. A typical usage for an tech organization is to allow staff users to see/edit comments, but not lambda users.
The plugin requires Redmine version 2.5.0 or higher.
Private comments have been added in Redmine 2.2.0 and this plugin was originally made for Redmine < 2.1.0. It now uses Redmine's default feature and old plugin's comments are automatically migrated to the standard Redmine feature. See http://www.redmine.org/issues/1554 for more informations.