You can close any Social Object you belong to, even if you didn't create it. Closing a Social Object prevents people from adding new messages to it and removes it from people's list of Social Objects.
To close a Social Object, click , then select Close <Social Object>.
To reopen a Social Object, from the navigation menu, select <Social Object>. In the Show menu, select Closed, then open the Social Object. Click , then select Reopen <Social Object>.
You can discard a Social Object only if you're the sole member. A discarded Social Object is removed from all lists, including collections and Social Objects it's related to.
To discard a Social Object, click , then select Discard <Social Object>.
For more information, see How do I close, reopen, or discard an item?