Adobe Acrobat Accessibility Techniques
http://www.webaim.org/techniques/acrobat/

WebAIM
2004

Abstract:

Some sites would hardly exist at all if they took down their PDF files (PDF stands for 'Portable Document Format'). This format is an incredibly useful format for some situations, providing a method to post content on the Web that will print exactly as the author intended it to. Creating PDF files is faster and easier than creating HTML files in many cases. This increases its allure for Web developers.