How accessible is PDF?

As a consistent PDF user, I was surprised to hear that the PDF format was not recognized as a standard format. Apparently, the W3C has some concerns about the accessibility of using PDF within Web sites.

Personally, I think that PDF is great for eBooks and other similar endeavors. However, using them within a Web site without any warning can be a real hassle. This is especially true for people that run slower PCs. Using PDF in cases like that can actually cause freezing and even crashing if the user is not alerted ahead of time. I mean, give them a chance to close some programs on their older machine first.

PDF is not recognised by the W3C as a standard format. The use of PDF content on Websites is covered, in part, by a number of Web Content Accessibility Guideline checkpoints including:

“Provide a text equivalent for every non-text element. This includes images, graphical representations of text …”
WCAG Checkpoint 1.1

“Ensure that pages are accessible even when newer technologies are not supported or are turned off.”
WCA Guideline 6

The lack of accessibility of PDF documents exposes Websites proprietors to the risk of legal action under laws in many countries that protect people against discrimination. In Australia, the Disability Discrimination Act requires the providers of goods and services through the web to ensure equal access for people with a disability.