How To: You've gone to a lot of trouble to get your PDF content together, why not go the extra mile to make them accesible and reader-friendly?"PDF is the monster from the Black Lagoon. It puts its clammy hands all over people with a cruel grip that doesn't let go."
At least, that's what usability expert Jakob Nielson has believed for the last 10 years.
Anyone familiar with Nielson's voluminous anti-PDF essays recognizes that, despite a few nuggets of common sense, he doesn't know much about the PDF document format. PDFs, he proclaimed in 2003, are "unfit for human consumption"—particularly onscreen and online. He stands by that opinion today, despite PDF flourishing among the world's governments, companies and people.
Nielson's gripes against PDF remind me of the Flat Earth Society, a group of people who espouse the sincere belief that the earth is a cube and all satellite and space shuttle imagery to the contrary—indeed, the entire U.S. Space Program—is an elaborate web of government disinformation (the Flat Earth Society is real; even I couldn't make this up).
Well, the earth is, in fact, round, and PDFs really can be read by humans. Here are a few finishing touches to make your PDFs even more reader friendly.
Bookmarks, TOCs, and Indexes
Think of the last technical book you opened. Odds are good that you didn't read it cover to cover, but rather rolled your thumb through the index or table of contents in search of a particular subject.
That behavior is identical to the way most people use other forms of documentation, including newspapers, magazines, Web sites, software help files, and multi-page PDFs.
Do your readers a big favor: Include a table of contents in your PDF. Even better, ensure that each entry in your TOC is a hyperlink to the chapter, sub-chapter, section, chart, or illustration referenced. Don't just include page numbers and expect your audience to scroll or use the viewer's page number field.
Creating and hyperlinking TOC entries is exceedingly easy to do in the most popular content creation tools. Microsoft Word (coupled with the PDFMaker plug-in) and Adobe's InDesign and FrameMaker all offer automated means of both generating TOCs and hyperlinking their entries to content. Learn how, and then use it.
In addition to putting a hyperlinked TOC onto pages toward the front of your PDF, create bookmarks that mirror (or expand upon) the TOC. Acrobat and similar PDF viewers support nesting of bookmarks several levels deep.
Include bookmarks for each chapter, then nest bookmarks to each section within that chapter. Create bookmarks for every heading level employed by your document. If your document contains charts, graphs, figures, illustrations, or callouts, bookmark those as well.
Once you have your bookmarks, show them to your readers by forcing the Bookmarks panel to appear when the PDF opens. In Acrobat, go to File > Document Properties > Initial View, and there set the Show drop down to "Bookmarks Panel and Page."
Include a bookmark to the cover or first page as well; this allows readers an easy return to a familiar point of reference.
For long documents and PDFs on intranets and fixed distribution media like CD-Roms, build an Acrobat index file to help users find precisely the information they want.
Metadata
A quick Google search for "PDF" will turn up hundreds of thousands of indexed PDFs. Most search engines and Web servers index not only the content of PDFs, but also their metadata. Help your PDF be found, categorized, and archived correctly and efficiently by filling out the basic document metadata of title, author, subject, and keywords in Document Properties.
For even more control over document filing—including the ability to add copyright information and more advanced XML data—click the Additional Metadata button in the Document Properties to access Adobe's XMP dialog.
On the Advanced tab of Document Properties you can also set the document's language, which will also help in classifying your PDF and presenting it to the right people.
Enable Commenting
People like to make notes in the margins of documents, and they like to highlight passages of text so they can easily find them again. Can readers make notes to themselves in your PDFs?
Unless you have a compelling reason not to, enable commenting on your PDFs. And don't just set it in the document security; specifically choose Enable for Commenting in Adobe Reader from Acrobat's Comments menu and Tools > Typewriter > Enable Typewriter Tool in Adobe Reader. This simple kindness will empower your readership to personalize the PDF to their needs without printing it out (which you may have disabled anyway).
Adding the usability enhancements discussed in this article will go a long, long way toward making your PDFs more reader friendly, and thus, more likely to be read. And, they should be read, no matter what Jakob Nielson would have you believe.
In part two, I'll recommend a few more ways to extend and enhance the usability of your PDFs.
Document Management 
