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Re: PDF: Alternative text for endnotes


From: Philip Kiff
Date: Apr 28, 2021 7:45AM

This is a great question. I've wondered similar things about the best
practice for formatting <Link> tags, and have wondered if I'm doing the
right thing. I have two comments here.

First, I don't think that PAC3 requires Alternative text applied to a
<Link> tag. What it requires I think is that you set the "Contents key
of link annotations". This is a setting that is difficult to get at
without software beyond Adobe Acrobat DC Pro. If you use axesPDF
QuickFix or CommonLook PDF, you can quickly set this for all the links
in your document. But if all you are using is Adobe Acrobat Pro, then I
think what may happen is that if you set the "Alternative Text" property
of the Link tag, then PAC3 will pass the check for the "Contents key".
As far as I know, there is still no Assistive Technology that consumes
this "Contents key" info in a PDF, which makes setting it something that
is done for technical reasons in order to pass PAC3 or to meet PDF/UA
specs, rather than something that is done in order to make any real
improvement to the PDF for current screen reader users?

Second, just FYI, I only apply alternative text to links that require
explanation. I specifically don't apply them to URLs in Bibliographies
and Reference lists like the ones you describe, for exactly the reason
you explain. In my case, I use axesPDF QuickFix to add the Contents key
to link annotations, so none of the links show up as errors in PAC3. But
I do add alternative text to other links in a document that appear in
the text as full URLs: I usually look at the web page and then add the
page's title as the Alternative text for the Link.


Philip Kiff
D4K Communications

On 2021-04-28 09:14, Alan Zaitchik wrote:
> I am working on a PDF with extensive bibliographical endnotes. My question concerns the best way to handle these <Note> structures aggregated at the end of the document. Each note contains a number, a full bibliographical citation (author, title, journal name, volume/number/year+pages), and most often a link to the article if available online. The link (Link-OBJR) itself, the clickable area, is not the entire note body but only the web address of the article, i.e. the URL. Thus the structure looks like
> <Note>
> <Lbl> 1 (2,3,…)
> <Span>(s) author, title, journal name, volume/number/year+pages
> <Link>
> <Span> url of the article
> Link-OBJR
> My question: Must the <Link> node have ALT text?
> My reasoning: It would be annoyingly to the screen reader user to set ALT text on the link as the citation text (author+title+ journal name+volume/number/year+pages). That is already (and properly) the text of the Note- and will have just been read out to the user. It would be even more pointlessly redundant to use the text of the Link node (the URL) as an ALT text, of course.
> SO I am tempted to specify NO alternative text for this <Link>, even though that will generate a PDF/UA accessibility failure in PAC3 (e.g.). I believe I could defend this decision if challenged.
> Is this the best practice or is there some plausible alternative I have missed?
> (For example, one crazy possibility would be to artifact away the citation text of the <Note> and use that as the ALT text of the <Link>! Is that actually beneficial to anyone, however? I think not.)
> Your wisdom on this is most welcome!
> Thanks,
> Alan