Show Your PDF Files to Google, Get More Organic Search Traffic

SEL - While search engines do “read” and index PDFs, search engines’ capabilities tend to lag new versions of Acrobat. Although Acrobat 8 is out, for now you should save your PDFs as version 1.6 (Acrobat 7) or lower to ensure search engines can index the content.

It seems like the vast majority of PDFs are without specified document properties, the most important of which is the Title. The Title property, if present, almost invariably represents the words that will be displayed as the heading of the search result. It’s the equivalent of the html title tag. If you don’t complete the Title property, the search engine is going to generate a title from the PDF’s content, and it may not be what you would choose. Link.