PDFDecoder, a companion module to Boolean Search 2 is a high-performance plug-in which extracts information from Adobe Acrobat PDF files.
Here's how it works... Boolean Search calls PDFDecoder to extract all the text from a PDF file so the words it contains may be indexed. Boolean Search also calls PDFDecoder to obtain information from PDF files for inclusion on search results pages, and all PDF attributes are displayable using special Boolean Search template tags.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.