[Irl-dean] Accessibility of PDF Format Resources?

Joshue O Connor joshue.oconnor at ncbi.ie
Thu Nov 16 15:41:06 GMT 2006

Hi Barry,

You made some very good points in your paper and thanks for the
background information.

> Early versions of the PDF format (and PDF reader software) lacked support for specific features needed to properly support a
 wide variety of users with disability. This was because PDF evolved
from the earlier "Postscript" format, and was initially still
primarily a "page description language" - i.e., it was optimised for
describing visual layout and appearance in print media,
rather than being tailored for the sorts of digital, semantic,
transformation which are of most benefit to people with disabilities.

I didn't realise that the format was an evolution from PostScript, and
in some ways that does explain its limitations, or at least the
limitations of legacy PDF's (pre version 4.0). Current 'accessible'
PDF's must obviously contain more than mere page description and layout

> It is possible, in principle, for authors and publishers to produce so-called "accessible PDF" - a form of PDF in which the specific 
features and techniques needed to support accessibility for users with
disabilities have been properly applied. But the difficulty is
that this form of PDF cannot be "automatically" generated, with
essentially zero extra effort, from existing print-oriented tools and
It requires significant, and appropriately skilled, manual effort to
prepare documents in this way.

Exactly, and that was also my point when I was talking about the 'skills
gap' in my last post. This is very much the Achilles heel of the format
which points to a deeper issue where skilled human intervention is
needed and automated processing fails, (even though PDF can 'simulate'
structure from non-tagged PDF documents), its a less that ideal
solution. My concern is that organisations that purchase
Acrobat Pro because it has built in accessibility features that allow
the author to tag the document, think that this *automatically* happens.

> Based on the above considerations, our recommendation is that, in the case of the great majority of documents currently being 
published on the web in PDF format, these should be accompanied by fully
accessible, X/HTML+CSS versions, conveying all the
same content and functionality.

Couldn't agree more. And I would add to that by saying; Even if an
author creates an all singing all dancing 'accessible' PDF they *still*
should produce an accessible (X)HTML/CSS version of the document.


Barry McMullin wrote:
> Hi Folks -
> This has been on the backboiler for a while, but I have finally
> produced a brief white paper on the vexed question of PDF and
> accessibility.  It's available here:
> <http://eaccess.rince.ie/white-papers/2006/pdf-eaccess/>
> I *think* it presents a fairly common sense and realistic
> statement of the situation; but I haven't been able to locate any
> existing resource which clearly addresses the points I raise, so
> I thought it was worth putting out into the public domain.
> Anyway, I would greatly appreciate any feedback!
> Best regards,
> - Barry.
> _______________________________________________
> Irl-dean mailing list
> Irl-dean at list.eeng.dcu.ie
> http://list.eeng.dcu.ie/mailman/listinfo/irl-dean


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