Adobe Acrobat 7 Professional - Manual (Page 267)

Adding attachments as comments
Acrobat allows you to add a file or audio attachment as a comment by using the Attach A
File As A Comment tool on the Commenting toolbar. To view an attachment, the reader
must have an application installed that can open the attachment. Comment attachments are
tracked with other comments in a review workflow, unlike file attachments that you add
using the Attach A File tool. Comment attachments appear in the Attachments tab with a
page number indicating their location. Audio attachments appear in the Comments List.
For information about adding audio clips and movies to a PDF document, see Integrating
media into documents .
Related Subtopics:
Using the Record Audio Comment tool
Using the Attach File As Comment tool
Pasting an image from the Clipboard