A plus sign (+) appears next to an item in the Navigator pane to indicate that this item contains subordinate items within it. These subordinate items are not visible when the plus sign appears. To display the hidden items, click a plus sign (+) in the list in the Navigator pane. The next level of subordinate items become visible, and the plus sign changes to a minus sign (-):
In the example above, the previously hidden items that appear when you click the plus sign could also contain hidden items themselves, indicated by a plus sign (+). In this example, Entry Management contains two items, which themselves contain hidden items.