Method:
This requires that users be provided a link to download any software needed to view page content.

All Java applets, scripts, and plug-ins (including Acrobat PDF and Powerpoint files) and the content within it are  accessible to assistive technologies, or else an alternative means of accessing equivalent content is provided such as html code.

Several barriers exist when using PDF files.  Most developers convert to a image PDF format.  This can create barriers with multiple column images.  Documents scanned into system and are  converted to one image; text cannot be accessed.  This makes PDF files not fully or easy to achieve accessibility.  Often the file lacks a textual equivalent for the image file.    Some ways to help make PDF files accessible is to provide information in PDF in other more accessible format such as an HTML format.   Also identify the link as a PDF and provide file size within the link text to a PDF.  And remember to provide a link to download the Adobe Reader which is needed to view PDF files.