Image (click to enlarge):

Steps:

To add an annotation to a file or category:
 
  1. First, click on the icon for the file or category you wish to add an annotation to.
      
  2. Click the "Add Annotation" button on the toolbar.
     

  1. An annotation window will appear below the file.  Click there and type text for your annotation.
      

 
To remove any annotation:

  1. Select the file that has the annotation.
     
  2. Click "Remove Annotation"