PDF and accessibility
PDF can be accessible to people with disabilities. Current PDF file formats can include tags (essentially XML), text equivalents, captions and audio descriptions, and other accessibility features. Some software, such as Adobe InDesign, can output tagged PDFs automatically. Leading screen readers, including Jaws, Window-Eyes, and Hal, can read tagged PDFs; current versions of the Acrobat and Acrobat Reader programs can also read PDFs out loud. Moreover, tagged PDFs can be reflowed and zoomed for low-vision readers.
However, many problems remain, not least of which is the difficulty in adding tags to existing or “legacy” PDFs; for example, if PDFs are generated from scanned documents, accessibility tags and reflowing are unavailable and must be created either by hand or using OCR techniques. Also, these processes themselves are often inaccessible to the people who would benefit from them. Nonetheless, well-made PDFs can be a valid choice as long-term accessible documents. (Work is being done on a PDF variant based on PDF 1.4. The PDF/A or PDF-Archive is specifically scaled down for archival purposes.)
Microsoft Word documents can be converted into accessible PDFs, but only if the Word document is written with accessibility in mind – for example, using styles, correct paragraph mark-up and “alt” (alternative) text for images, and so on.