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Thread: Reference tag with ALT text
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From: Alan Zaitchik
Date: Wed, Apr 22 2020 8:03AM
Subject: Reference tag with ALT text
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I just saw something I never knew could be done. Works in JAWS, but I'd like to know if this is legit.
In a PDF table there's a numbered footnote reference. The author created a Note tag around the number and added an empty Reference tag inside the Note. The Reference tag has as its Alt text the actual content of the footnote. The content is not in a Paragraph tag inside the Reference, as I have usually seen. There's no tag elsewhere in the tag tree for that content. It's just the Alt text of the empty Reference tag.
Obviously this forces the user to hear the note while reading the main content, but on the plus side this supports the note's content being reused multiple times since it's just adding multiple Reference tags with the same Alt text.
Is this a common practice? Do all screen readers support Alt text on a Reference tag?
Thanks,
Alan
From: chagnon
Date: Wed, Apr 22 2020 9:01AM
Subject: Re: Reference tag with ALT text
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No, that construct is incorrect.
Refer to the PDF Association's Syntax Guide at https://www.pdfa.org/resource/tagged-pdf-best-practice-guide-syntax/, specifically sections 4.2.7 <Note> and 4.2.8 <Reference>
There's no need to have Alt-text on the standard construct. If the Alt-text just repeats the exact live word content in the PDF, then it provides no additional information whatsoever, and may also remove some functionality/controls for the A T user.
Trying to envision what this looks like: <Quote> The Reference tag has as its Alt text the actual content of the footnote. The content is not in a Paragraph tag inside the Reference, as I have usually seen. There's no tag elsewhere in the tag tree for that content. <End Quote>
If the actual content of the footnote is in Alt-text on the <Reference> tag, then how do other users get access to or see the footnote? Alt-text is generally available only by screen readers and other text-to-voice A T.
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From: Philip Kiff
Date: Wed, Apr 22 2020 11:22AM
Subject: Re: Reference tag with ALT text
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Mmmmm....I think Alan may be trying to get at the question of whether
this syntax may be acceptable in cases when there is a single note that
is referenced multiple times. And in such cases, I'm not sure that the
PDF Association's best practice guide is helpful? In 4.2.7.3 Creation
(on page 37) of their guide, they imply that their recommendations are
only fully reliable when:
- the label is not repeated elsewhere in the document, or
- the same-labelled <Note> follows the <Reference> in the logical
reading order.
Coincidentally, I'm right now finishing off a long, official legal
document where I used almost this exact same tagging structure in order
to tag multiple instances of a symbol which is intended as a marginal
note to identify passages that have changed in the document since the
last revision. In my case, I did not create an empty reference tag.
Rather, I enclosed the symbol with an <Lbl> tag and then placed the
<Lbl> as a child of a <Reference>. Then I applied alternative text to
the <Reference> tag just like the case Alan mentions. So the tag tree
looks like this:
<Reference> (with alternative text)
 - <LbL>
- - symbol
To complicate matters, In my case, the <Note> that the <Reference>
refers to actually precedes the <Reference> symbol in the document, so
my file doesn't meet either of the criteria set out in item 4.2.7.3 of
that PDF Association guide.
Alan's example is almost the same as mine, except that document employs
an empty <Reference> tag. But by simply reversing the nesting order, and
using the <Lbl> tag instead of the <Note> tag on the number, then the
tagging in the document he cites would be correct, wouldn't it?
(Assuming that there is indeed a <Note> somewhere that is being
referenced with that <Lbl> number.
In any case, like, Alan, I thought that this was pretty good solution to
the challenge of managing multiple references to a single note when one
is dealing with a document whose text and format cannot be altered. But
I also did not do robust testing to see whether this syntax would be
properly consumed by multiple different assistive technologies.
The only other viable option that I've seen for dealing with such
structures (multiple references to a single note ), is the one put
forward by Ted Page from Accessible Digital Documents here:
https://accessible-digital-documents.com/blog/accessible-pdf-footnotes-endnotes/
Phil.
Philip Kiff
D4K Communications
On 2020-04-22 11:01, = EMAIL ADDRESS REMOVED = wrote:
> No, that construct is incorrect.
>
> Refer to the PDF Association's Syntax Guide at https://www.pdfa.org/resource/tagged-pdf-best-practice-guide-syntax/, specifically sections 4.2.7 <Note> and 4.2.8 <Reference>
>
> There's no need to have Alt-text on the standard construct. If the Alt-text just repeats the exact live word content in the PDF, then it provides no additional information whatsoever, and may also remove some functionality/controls for the A T user.
>
> Trying to envision what this looks like: <Quote> The Reference tag has as its Alt text the actual content of the footnote. The content is not in a Paragraph tag inside the Reference, as I have usually seen. There's no tag elsewhere in the tag tree for that content. <End Quote>
>
> If the actual content of the footnote is in Alt-text on the <Reference> tag, then how do other users get access to or see the footnote? Alt-text is generally available only by screen readers and other text-to-voice A T.
>
> â â â
> Bevi Chagnon, founder/CEO | = EMAIL ADDRESS REMOVED =
> â â â
> PubCom: Technologists for Accessible Design + Publishing
> consulting ' training ' development ' design ' sec. 508 services
> Upcoming classes at www.PubCom.com/classes
> â â â
> Latest blog-newsletter â Accessibility Tips at www.PubCom.com/blog
>
>
From: Duff Johnson
Date: Thu, Apr 23 2020 7:29AM
Subject: Re: Reference tag with ALT text
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> Mmmmm....I think Alan may be trying to get at the question of whether this syntax may be acceptable in cases when there is a single note that is referenced multiple times. And in such cases, I'm not sure that the PDF Association's best practice guide is helpful? In 4.2.7.3 Creation (on page 37) of their guide, they imply that their recommendations are only fully reliable when:
> - the label is not repeated elsewhere in the document, or
> - the same-labelled <Note> follows the <Reference> in the logical reading order.
That is correct. The problematic use case you mention (a single note referenced multiple times) is due to a weakness in the PDF 1.7 specification. This was addressed in PDF 2.0 (published in 2017), but implementers have yet to catch up.
The Best Practice Guide you referenced is all about PDF 1.7, as this is still (today) typical PDF technology.
Duff.
From: Philip Kiff
Date: Mon, Apr 27 2020 5:26AM
Subject: Re: Reference tag with ALT text
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In the absence of additional opinions from the list, I'll venture to
confirm that the revised tagging structure for the case you've described
seems almost correct to me. The one thing I would change is that the way
you've written it makes it appear that your <Note> tag is at the same
structural level as your <P> or Paragraph tag. Normally, I think, <Note>
tags are found nested within <P> tags because they are "inline"
elements, whereas <P> tags are "block" level elements. Some automated
accessibility tests will flag <Note> tags sitting at a block or root
level with warnings or errors. So, when a <Note> is standing alone at
the bottom of a table or page somewhere, I typically nest it inside an
otherwise empty <P> like this:
<P>
- <Note>
- - <Lbl> "1"
   Text: "content of the shared footnote..."
Regarding the use of alternative text to apply Note content to the
Reference tag, as I already mentioned, that is a tagging structure that
I personally have used just this month. And I believe that in my case,
it was the best solution available, and I think that it is an acceptable
tagging practice in terms of currently supported PDF specifications and
guidelines. But I don't know if anyone else is using this practice, and
to my knowledge it has not been tested across different assistive
technologies.
Phil.
On 2020-04-23 10:13, Zaitchik, Alan wrote:
> Thank you, Bevi and Phil!
> I probably described the case I encountered in less than precise fashion, so I will try again. Excuse the prolixity.
> Since I cannot ask the user to implement a Javascript-based solution I wonder if I can satisfy all your objections with a slight change in the tags. This hews close to Phil's suggestion.
>
> The original case was something like this (removing the Table-related context of the original since it is irrelevant).
> <Paragraph>
> Text...
> <Note>
> <Reference> with alt text "content of the shared footnote..."
> Text: "1"
> Text...
> ... more page content, etc. ...
> <Paragraph>
> Text...
> <Note>
> <Reference> with alt text " content of the shared footnote..."
> Text: "1"
> Text...
> ... more page content, etc. ...
> (artifacted away) "content of the shared footnote..."
>
> As you can see the content of the footnote ("content of the footnote ") is not tagged but remains visible where it was created, at the bottom of the page.
>
> Your reactions and other objections include the points that
> (1) the structure of a <Note> containing a <Reference> is mistaken
> (2) the note content should be a tagged element in the reading order
> (3) the reference text "1" is not implemented as a Label
>
> Would the following be acceptable? I think it is more or less what Phil did.
>
> <Paragraph>
> Text...
> <Reference> with alt text " content of the shared footnote..."
> <Lbl> "1"
> Text...
> ... more page content, etc. ...
> <Paragraph>
> Text...
> <Reference> with alt text " content of the shared footnote..."
> <Lbl> "1"
> Text...
> ... more page content, etc. ...
> <Note>
> <Lbl> "1"
> Text: "content of the shared footnote..."
>
> On the downside:
> A screen reader user is forced to hear the footnote content inline, whether s/he wants to or not.
> Updates to footnote content (or translation to another language) now must update multiple instances of the text.
>
> On the upside:
> This solves the "multiple references to the same footnote" problem.
> No javascript is required.
>
> I could see insisting on a Javascript solution (Ã la Ted Page) if the footnotes should remain optional, e.g. if they are lengthy or of a limited interest-- but adding Javascript may not always be possible. And anyway the Javascript solution still suffers from the second drawback of the above proposal.
>
> Alan
>
>