Comments can be imported from either an FDF or XFDF file into the current document. Comments from Text Annotations, Graphics Annotations, and Sound Annotations will be imported. When imported the comments will show up in the exact same location on the page as when they were exported.
Comments can be imported using the following formats
FDF: File format created by Adobe that is supported by most PDF applications
XFDF: Extended FDF file format created by Adobe that is supported by most PDF applications