Block all unmanaged add-ins

This policy setting blocks all add-ins that are not managed by the "List of managed add-ins" policy setting. If you enable this policy setting, and the "List of managed add-ins" policy setting is also enabled, all add-ins are blocked except those that are configured as 1 (always enabled) or 2 (configurable by the user) in the "List of managed add-ins" policy setting. If you disable or do not configure this policy setting, users can enable or disable any add-ins that are not managed by the "List of managed add-ins" policy setting.