In the late 1990’s, Adobe (http://www.adobe.com) introduced the PDF, or Portable Document Format. PDF documents are particularly useful for preserving layout and font information regardless of software and hardware platforms. Additionally, many authors enjoy having control over tighter document security, which has made PDF and variants of the PDF popular for E-Book publishing and online forms.
In the early days of PDF authoring, there were no facilities available for making these documents accessible. There are still numerous legacy documents which are simply bitmap images of documents viewable in the Adobe Reader or some similar application. The only means of achieving accessibility for these documents is with optical character recognition (OCR) software.
This is not considered a true form of accessibility, but it can make some content usable when modern accessibility conventions are not honored.
In recent years, most publishing platforms, such as Adobe InDesign or MS Word can generate accessible PDF documents. These documents will be most accessible if document structure and formatting tools are used. For example, use of headings, rather than simply using a larger or bold font, or creating columns using the “column” option in your software package of choice rather than using tab settings or spaces.
Adobe Acrobat also now features an Accessibility checker. This is a good means of identifying common fixes which may help to improve accessibility. PDF tags can also be manipulated with Adobe acrobat. These tags have no effect on the visual appearance of a PDF document. They simply provide contextual information which helps accessibility software and automated tools such as search engines to properly identify parts of documents.
Many accessibility experts still suggest providing alternative documents such as HTML when possible. As PDF viewers often require a plug-in or other PDF viewing software of some form, accessibility can be cumbersome. The Portable Document Format is alive and well on the Web and will be with us for the foreseeable future. Tutorials and videos on using the accessibility features
of all of their products can be found on the Adobe Website.
