Adobe Acrobat 7 Professional - Manual (Page 304)

Finding comments
You can use a special comment search feature to find specific comments based on their
text.
To find a comment:
1. Click the Comments tab to display the Comments List.
2. Click the Search Comments button on the Comments List toolbar.
3. In the Search PDF window, specify the word or phrase you want to search for, and then
click Search Comments.
For information on additional search options, see About searching text .