Working with Markups > Annotation Sets and Folders > To Open an Annotation Set
  
To Open an Annotation Set
In the primary panel, click Annotation Sets, and then perform one of these operations:
• Double-click the annotation set.
• Drag the annotation set into the graphics area.
• Right-click the annotation set and choose Open in New View from the shortcut menu.
• Right-click the annotation set and choose Replace View from the shortcut menu, and then select a view name to replace with the annotation set view.
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To toggle between the types of display for the Annotation Sets pane, right-click and select Switch to List View or Switch to Tree View.