Re: PDF's and Signatures

> I have to disagree slightly with Andy’s claim – PDFs *are* covered-by and included in WCAG

To a degree, There are many facets of PDF that WCAG does not cover. For a complete understanding of PDF accessibility it is necessary to look to PDF/UA, the ISO standard for accessible PDF.

> , and in fact there is a whole section of Success Techniques provided by the W3C. Please see:

While many of these are useful, some are simply wrong, misleading, or both. Additionally, these techniques represent only a modest fraction of what’s necessary to guarantee an accessible PDF.

> I think the issue(s) you will find problematic include how to render that wet signature to non-visual users (it’s not text, so OCR etc. will struggle to dealinclude a graphic of a signature, you will of course need to also provide appropriate alt text (I would likely counsel this: alt=”[Signature: Mickey Mouse]”)

One must distinguish between an ink signature (which is simply a graphics object requiring alt text to be accessible) and a digital signature, which is a property of the document itself, and should be exposed by AT accordingly just as is other document metadata.

> I am personally unaware of the current state of accessibility and digital signatures on PDFs, although my first guess is that it is likely not perfect, buta robust and long-standing (if still imperfect) tool in their shed. Perhaps Andrew might have a comment here (?)

So far as I am aware the digital signature UIs in Adobe’s tools are as accessible as the rest of Adobe Acrobat / Reader’s UI. This has *nothing* to do, however, with an “ink” signature, which is simply a pretty picture on the page, and like all other pictures, needs alt text to expose it to all forms of AT equally.


Received on Thursday, 22 January 2015 14:47:58 UTC