PDF stands for Portable Document Format. On this site you will see this symbol
where there is a PDF document to access. You can do this by simply clicking on the name of the document (which will look like a normal link). If nothing happens or you get an error message, you may need to download a free plugin to view the document, called Acrobat Reader. There is also an accessible version, for use with screen readers - visit the Access Adobe website for further information. PDF is often used for information which is not easy to convert to html pages, such as complicated tables or charts, or which people are more likely to want to print off or store on their computer to read at their leisure.
To view PDF documents you may need to download a free plugin called Acrobat Reader. The most recent version - Adobe Acrobat Reader 5.1 - includes support for screen readers (Accessibility) via the Microsoft Active Access API (MSAA). Download Acrobat Reader 5.1
You can also convert Adobe Portable Document Format (PDF) documents on-line into either HTML or ASCII text, which can then be read by a number of common screen reader programs.