Specify the appearance of text box comments
in your PDF documents by choosing Edit > Preferences > Comment.
In the Text
Box Default Font area, select a font name, size and an underline
style from the drop-down lists. Choose a font color and specify combinations
of other text attributes such as Bold, Italic, Superscript, Subscript
and Strike through.
In the Text
Box Default Align area, choose Left, Center, Right or Justified
alignment for your text in comment boxes.
Click Reset
Comment Defaults to restore delivery-time settings.
Annotating
and Marking up Documents provides a set of links to each comment type.
See also Print with comments.