Adobe ACROBAT READER 7.0 Manual page 195

About file attachments
If an Adobe PDF document includes additional usage rights, you can attach PDF and other
files to the document so that the reader can open it for viewing. If you move the PDF
document to a new location, the attachments automatically go with it. You can add two
types of file attachments to PDF documents from the File toolbar: document-level
attachments and page-level attachments. Document-level attachments are added by using
the Attach A File tool . Page-level attachments are added as comments by using
various tools to add sound files and documents. (See Adding attachments as comments.)
Comment, or page-level, attachments display the File Attachment icon or the Speaker
icon on the page where they're located.
If a PDF document contains an attachment, the File Attachment icon appears in the
status bar. You can view the number of attachments by placing the pointer over the icon.
The Attachments tab lists all the attachments in the PDF document, including the name, a
description, the modification date, and the file size. Page-level attachments also include
the page number of their location.