Discussions are like a forum attached to a piece of
  content. Wherever the document is moved, the discussion goes with it. They
  provide an ideal way to record decisions or annotations about a document
  without changing the content.
    - Navigate to the content item system-overview.html (now located in the Published space).
 - 
        In the Content Items pane, click 
 for this item and select
        Start Discussion.
       - 
        On the Create Topic page, enter the
        discussion details and click Create
        Topic.
        

 - 
        To view a discussion on an item, click 
(View Discussions) associated with the content
        item.
       
If you check out a document that has a discussion, the working draft will not have that discussion. However, if you start a discussion on a working copy when it is checked in, the discussion is added to the original item with a date stamp. While content is checked out, the original content is locked but discussions can still continue on it.