Commenting tools are available only
in PDFs that have commenting enabled. PDFs in a review workflow
typically include commenting rights. Use the Attach File As Comment tool to embed a file at a selected location in a PDF, so that the reader can open it for viewing. By adding attachments as a comment, you can reference longer documents that can’t easily be pasted into a pop-up note or text box. If you move the PDF to a new location, the embedded file automatically goes with it. To view an attachment, the reader must have an application installed that can open the attachment.