A group with the following restrictions:
- All comment posts through the UI have an extra confirmation step.
- Comment posts through email are not allowed.
These extra precautions are useful if several groups share the same documents that they can comment on privately but would like to share some comments between them. To do this, the documents must be also shared to the common group and common comments posted to that group.
In this scenario, the groups would usually by made subgroups of the common group so they all have access to those comments.