Adobe PDF is a common document format used on websites for sharing documents that require specific printing requirements. The accessibility of PDF documents is much different than HTML documents and the accessibility is largely controlled by the tools used to create the PDF document.If the PDF document is created in tools like Microsoft Office with Adobe Acobat installed or Open Office there is are a number of ways to make an accessible PDF document using some failry simple proceedures for documents that are primary text with some tables and simple graphics.If the PDF document is created through scanning print version of the document accessibility will be more difficult and manually be added to the document. The best practices outline the features need for the resulting accessibility Adobe PDF documents.
There are three parts to a PDF document that effect accessibility:
- Physical View: The default graphical rendering of the document
- Content View: The text representation of the physical view
- Tags View: The HTML like markup that provides semantic structure for the text content view
For an Adobe PDF document to be accessible it must include an accurate representation of the text of the graphical rendering and the tagging mark must represents the structural relationship between the graphical rendering and text represenation, and the tags must represent the structural role of the text in document (heading, list, table, image/figure, ... )..