Callout
Click the 
Callout tool in the Comment Toolbar to add comments as callouts. A callout is a text box with an arrow.
Click on the page to open a callout text box and enter text. If necessary, the box expands to accept longer texts. When entering a text, make a selection, right-click in the box and choose Properties… from the shortcut menu to modify text properties for the selection in the toolbar shown below.
Select the Hand tool as soon as you have all the callouts you need.
To change text properties of a previously created callout, select it with the Hand tool in the Standard Toolbar or the Callout tool in the Comments toolbar and double-click to have access to its content. Make a text selection and right click, then choose Properties to access the following toolbar:
Click Set to specify current settings as default, or specify default values for text boxes and callouts by selecting Edit > Preferences > Comment.
To move or resize a callout , use the 
Select Object tool in the Standard Toolbar or the Hand tool. You can move the object as a whole, the text box only or the arrow.
To change the appearance of the callout, right-click and choose Properties… to specify style, thickness and color for the box border and arrow, a fill color and opacity value for the text box, and a style of the arrowhead. You can also access the Author and Subject, and History properties. To avoid accidental modification, choose the Protected checkbox.