An icon data callout and its dialog box.
Icon callouts, or as Visio calls them, icon sets, are great at indicating conditions. In the column to the right of the equals boxes, you type the values to trigger a particular icon. In this exmaple, if a server has data in the Status column that is equal to OK, a check mark icon will appear for that shape. If a server has data in the Status column that is equal to Unavailable, an exclamation mark icon will appear. And if the Status is equal to Unknown, a question mark icon will appear.
