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Re: PDF/UA footer artifact discussion

From: Duff Johnson <duff@duff-johnson.com>
Date: Sun, 10 Mar 2013 18:35:43 -0700
Message-Id: <1BE1DBC9-F412-4050-8D26-951AB9C5B9BA@duff-johnson.com>
To: w3c-wai-ig@w3.org
Jonathan,

I understand the concern, especially given current-generation AT, which doesn't do anything with artifacts (so far as I know) apart from ignoring them completely, which isn't how they should be treated. PDF/UA requires conforming AT to be able to report artifacts to the user on request.

Unfortunately, there's no good (or even acceptable) solution in Tagged PDF, as of PDF 1.7, for page headers and footers unless artifacts are supported. 

Including page headers and footers in the logical structure is plainly wrong; this content isn't part of the document. Page header and footer content is "metadata for the physical page" - no more. Including such artifacts in the logical structure would not necessarily advise users of page-numbers (because it's "just a number" out of context) and certainly, would routinely introduce confusing breaks in the logical flow, sometimes occurring within words, sentences or paragraphs.

Regarding the common case of physical page numbers that differ from the PageLabel, note that the Technical Implementation Guide also says:

"In order to facilitate page-based navigation to end-users, the contents of the PageLabel tree should match the logical pagination of the document whenever possible."

The PDF Association, by way of its "NVDA goes PDF/UA" project, is supporting the ongoing development of support for PDF/UA in this leading screen reader. The subject of artifacts has been discussed with NV Access, and they are studying their approach to the question.

Regarding WCAG 2.0… given the current limitations of AT the present-day workaround for ensuring that page and section information is provided to AT users on a per-page basis is to set these values in the PageLabels.

I'd like to suggest you attend a meeting of the US Committee for PDF/UA, where we can have this discussion in a forum in which we can take direct action to improve the Technical Implementation Guide, if necessary. In addition, I'm sure the committee would love to get your input as it considers this question (among others) for PDF/UA-2.

Duff.




On Mar 10, 2013, at 4:51 PM, Jonathan Avila <jon.avila@ssbbartgroup.com> wrote:

> There is one item in PDF/UA that I believe needs to be addressed and discussed.  I’m raising the issue here to get others opinions as it relates to WCAG conformance.  The PDF/UA specification indicates that repeating headers and footers, page numbers, Bates numbers, etc. must be artifacts in order for a document to be PDF/UA conformant.      Many documents contain very important information in the footer including page/section numbers that do not correspond to the PDF reader’s displayed page numbers.  These important page numbers and sections may be referenced in the document text.  Additionally, important form information such as tax forms contain numbers and version of the form in the footers – access to the information is absolutely necessary for users with disabilities.  Furthermore, Bates numbers may contain copyright information that users need access to.  Artifacting this information prevents access by users with disabilities and would cause a document in my opinion to not conform to WCAG 2.
>  
> The Technical Implementation Guide that AIIM has posted on PDF/UA http://www.aiim.org/Research-and-Publications/standards/committees/PDFUA/Technical-Implementation-Guide indicates the following:
>  
> 7.1 is the core of PDF/UA; it contains most of the essential concepts pertaining to page-content.
> Paragraphs 1 and 2
> The following elements of a page's content should always be understood as "Artifacts".
> •Repeating headers or footers, even if entered by a user.
> •Slide backgrounds, even if user-defined.
> •Page numbers.
> •Usually, any items that tend to repeat page after page.
> •Bates numbers (NOTE: ISO 32000-2 will introduce a new type of artifact to contain Bates numbers)
> Artifacts can never be a part of the logical structure tree. As PDF/UA-1 requires that page content is either contained in the document's semantic structure or marked as an artifact, all page content must be either contained in the logical structure or marked as an Artifact.
>  
> Is there is a way to reconcile PDF/UA and WCAG 2 in this area?
>  
> Best Regards,
>  
> Jonathan
Received on Monday, 11 March 2013 01:36:07 GMT

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