One of the guiding principles for the Visio 2010 user interface is that commonly used shapes should be easily accessible. These’re exposed directly in the Ribbon through shape galleries. A callout is an annotation on a diagram that provides more information about a shape. Callouts are Visio shapes themselves, which differentiates them from other forms of annotation such as comments. To add a callout shape in Visio 2010, select the target shape on the page and then click on the Callout dropdown in the Insert tab. You’ll see the Callout gallery with many different styles of callouts. Hover over a style to see it applied as a Live Preview and then click the style to add the callout. The callout appears slightly above and right of the target shape.
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