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Thread: PDF column tag
Number of posts in this thread: 10 (In chronological order)
From: Murphy, Sean
Date: Sun, Jul 24 2022 10:47PM
Subject: PDF column tag
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All,
When a document is using newspaper column style or has content in two columns. Does PDF have a column tag? If not, how do you fix the reading order for columns so the screen reader reads column 1, then column 2, etc. If someone can provide an example of the tagging.
Currently it is being done in a Table. This document is a template created by java and we require the right tags to give to the developers. I have looked up some references and couldn't find the info.
Regards
Sean Murphy
Sean Murphy | Senior Digital System specialist (Accessibility)
Telstra Digital Channels | Digital Systems
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From: chagnon
Date: Mon, Jul 25 2022 12:09AM
Subject: Re: PDF column tag
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You're describing the reading order of the document, and that is controlled in two areas of the PDF:
1: The primary reading order is the Tag Tree. All PDF/UA compliant assistive technologies should read (or process) the content in the order it appears in the Tags Tree. So check the tag tree.
2: The Order panel is used by some assistive technologies and it, too, should be in a logical order. Hopefully it matches the Tag Tree reading order, but that's not possible in some visual designs so make it match as closely as possible.
Learn more about the 4 reading orders in PDFs at https://pubcom.com/blog/2020_08-18_ReadingOrder/reading-orders.shtml
All of these reading orders are created based on how the original source document was created. So if you learn how to use Word, PowerPoint, and Adobe InDesign correctly, you shouldn't have reading order problems.
Reading across the columns, as Sean describes, can also be a problem with the screen reader or text-to-speech technology, not the PDF. Cheaper or older assistive technologies often can't correctly interpret a PDF correctly.
One key utility is Acrobat's built in Read Out Loud, which is an antiquated piece of crap programming. We do not recommend wasting any time using it to test PDFs for accessibility compliance â you'll only get false positives and false negatives. Test with a real screen reader such as NVDA or JAWS.
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From: Moiz Yamani
Date: Mon, Jul 25 2022 2:59AM
Subject: Re: PDF column tag
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Here are my views:
In a columnar layout, all the content of column 1 should be read first followed by the content of column 2. To achieve this, we need to tag the content using standard paragraph, heading, list etc. tags based on the content. There is no column tag available in PDF.
A screen reader will read the content of 1 cell at a time from left to right - top to bottom. So, tagging the columnar content using table tags is not a good option. If table tags can't be removed, then the table should comprise of 1 row so all of the content of column 1 will be read out first followed by content of column 2. Limitation with this approach is that screen reader users will have to unnecessarily go through layout table.
Thanks and Best,
Moiz Yamani | Digital Marketing Executive
BarrierBreak<https://www.barrierbreak.com/> & 247 Accessible Documents<https://247accessibledocuments.com/>
From: Duff Johnson
Date: Mon, Jul 25 2022 7:06AM
Subject: Re: PDF column tag
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HI Sean,
> When a document is using newspaper column style or has content in two columns. Does PDF have a column tag? If not, how do you fix the reading order for columns so the screen reader reads column 1, then column 2, etc. If someone can provide an example of the tagging.
There is no âcolumnâ tag; in PDF, text displayed in columns is tagged normally with heading, paragraph, etc. tags. The tags follow the flow of the text through the columns, but need not represent the columns themselves.
PDF does include âColumn attributesâ for grouping elements (see 14.8.5.4.7 in ISO 32000-2), however the PDF community has never actually determined that this attribute has an accessibility relevance. If someone can identify such a relevance I'd be delighted to take it back to the committees working on PDF/UA-2.
> Currently it is being done in a Table.
This is incorrect for text laid out in columns, as such content does not have table relationships.
Duff.
From: Duff Johnson
Date: Mon, Jul 25 2022 7:20AM
Subject: Re: PDF column tag
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Bevi makes excellent points, but I want to add a clarification…
It's better to think about âreading orderâ in a PDF in the following two ways:
- The so-called âOrder panelâ reveals the physical ordering of content on the page, but cannot reflect the logical ordering, so no headings, lists, tables, alt. text, etc, etc.
- The tag tree, by contrast, describes the logical ordering; consequently, only AT which processes the tag tree may be considered as supporting accessible PDF.
A rough analogy would be a text viewer, which is certainly capable of âreadingâ HTML, but it isn't a web browser, much less an accessible web browser.
Duff.
From: Karen McCall
Date: Mon, Jul 25 2022 7:40AM
Subject: Re: PDF column tag
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I agree with Bevi...avoid at all costs using the Read Out Loud "tool" in Acrobat or Reader. It is crap and we've been asking Adobe to make it a full screen reader since Acrobat 6, the version after it was introduced.
If you use the Column tool in Word (Layout Ribbon, Columns or Alt P, J) the tags will be correct in the tags tree. I use columns, both newspaper and parallel all the time. I am a person who uses a screen reader.
You would use a combination of section breaks and column breaks for some layouts using parallel columns but most of this is done automatically in Word as you design the layout and use Columns. I demonstrate this technique in my Word training. You can have a heading on the left and the associated content on the right, halfway down the page you can have an accessible sidebar with its associated text on the right.
You can check the "reading order" of columns in Word by switching to Draft view (Alt + W, E) which displays the text in a single column illustrating how the screen reader would read the text. This is not a screen reader specific view, it is a Draft, minimal view of the document contents.
PowerPoint has a Content placeholder option to put the contents of a placeholder in columns and this also translates to a correctly tagged (list tags) in PDF. Not an option I'd recommend for a slide with a lot of content but it is an option to display a list in a different, maybe more visual yet accessible manner.
Cheers, Karen
From: Alan Zaitchik
Date: Mon, Jul 25 2022 12:59PM
Subject: Re: PDF column tag
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I think it's worth adding that using table structures for âpresentationâ purposes only, rather than for expressing data relationships, violates Matterhorn 15-004 and will prove inconvenient for screen reader users.
Are you truly stuck with the tables?
Alan Zaitchik
From: Murphy, Sean
Date: Mon, Jul 25 2022 5:00PM
Subject: Re: PDF column tag
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Alan,
We are uplifting a legacy system that generates PDF files via a Java program. I have conversations with the team today on this and will share.
Regards
Sean Murphy
Sean Murphy | Senior Digital System specialist (Accessibility)
Telstra Digital Channels | Digital Systems
Mobile: 0405 129 739 | Desk: (02) 9866-7917
Diversity is having a seat at the table, inclusion is having a voice, and belonging is having that voice be heard
Submit an Engagement Accessibility form
Accessibility Single Source of Truth
From: Murphy, Sean
Date: Mon, Jul 25 2022 5:18PM
Subject: Re: PDF column tag
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Patrick,
I see the column attribute very important to inform the screen reader user of the document structure. This is possible in Windows Word with Jaws for Windows to obtain this information. PDF should provide the same capability as I see this linkage with 1.3.1 Information and Relationship. As it helps users understand how a document is being structured so they can reuse similar structure when they are creating their own documents. As this is a challenge for vision Impaired users in learning and understanding document structure if they have never had sight.
This feedback is from individuals in my network who want to create professional documents and always find this a challenge and want to be independence.
The flip side of course not knowing it is in columns layout doesn't impact readability as long as it is done right.
Regards
Sean Murphy
Sean Murphy | Senior Digital System specialist (Accessibility)
Telstra Digital Channels | Digital Systems
Mobile: 0405 129 739 | Desk: (02) 9866-7917
Diversity is having a seat at the table, inclusion is having a voice, and belonging is having that voice be heard
Submit an Engagement Accessibility form
Accessibility Single Source of Truth
From: Duff Johnson
Date: Mon, Jul 25 2022 6:09PM
Subject: Re: PDF column tag
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Hi Sean,
> I see the column attribute very important to inform the screen reader user of the document structure.
Can you help me to understand what you mean by âstructureâ in this case? Can you provide an example? As I understand âcolumns" (which flow down and then across the page, and are commonly seen in magazines and newspapers), they have little / no inherent semantics.
If, on the other hand, you mean that e.g., a left column contains content that maps to content on a center and right column, then a table structure would indeed seem appropriate.. but only in that case.
Last point: if the users' AT does not support PDF tags it won't matter how the document's structure is encoded with tables or as paragraphs and headings; they won't be able to perceive the structure as expressed via the tags.
Duff.