Click the Text Box tool in the
Comment Toolbar to make visible comments.
Drag a window and enter text. The text box expands to accept longer text.
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. To change text properties of a previously created text box, select
it with the Hand tool or the 
Select
Object tool in the Standard Toolbar
and double-click to have access to its content and the text toolbar.
Click Set to specify current
settings as default, or specify default values for text boxes by selecting
Edit > Preferences > Comment.
To move or resize a text box, use the Select
Object tool in the Standard Toolbar
or the Hand tool. To change its
appearance, right-click and choose Properties
to specify border style, thickness and color, a fill color, and an opacity
value for the text box. You can also access the text box Author, Subject
and History properties. To avoid accidental modification, choose the Protected checkbox.
Text added with this tool remains as an annotation. To add new text
to the real content of a PDF page, use the Typewriter
tool or the Typewriter
Box tool. To modify existing text, use the Touchup
Text tool.
Click the 
Callout
tool in the Comment Toolbar instead
of the Text Box tool, to add an arrow headed line pointing from the text
box to a place on the page.
