Yesterday Joe Clark published his long awaited article on PDF accessibility and it did not disappoint. It includes some excellent advice on when to use PDF and dispelled many of the accusations levelled against the format. If you use PDF on your site, you should read on.
Boo sucks to the PDF critic
The PDF format has always received a bad press for accessibility but Joe Clark’s article debunks many of these criticisms arguing that in many ways it is no worse than HTML. In fact, at one point in the article he actually argues that it has taken screen readers considerably longer to support HTML correctly, than it has PDF. He argues that posting a PDF online with no HTML alternative does not automatically constitute discrimination.
However, Joe’s article was far from being a ringing endorsement for the format. In particular, he identifies two specific problems not so much with the format itself but the way it is used:
PDF is overused
Firstly, he argues that the format is overused. The implication of the article is that many people use PDF simply because they are easier to create than converting content to HTML. Joe argues that in most cases content should be displayed as HTML unless PDF offers functionality that cannot be recreated in HTML. He goes on to list some examples of circumstances where PDF might be a more suitable solution.
PDF is badly tagged
Secondly, Joe argues that in most cases PDF is not marked up in such a way as to maximise accessibility. This is done using a tagging system that many people are completely unaware of and that can only be added by a limited number of software applications (such as Adobe Acrobat). Although "untagged" documents can still prove accessible, the likelihood of them being so is considerably reduced.