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Re: PDF reading order and tag order

for

From: Philip Kiff
Date: Jun 7, 2017 10:56AM

On 2017-06-07 12:18, Alan Zaitchik wrote:
> [....]
> But I have 2 questions.
> 1. The Acrobat Reading order tool jumps around with little regard (it
> seems) for my reordering and restructuring the tabs, even though I set my
> 'Preferences' for reading order to 'Infer from document structure'. Is
> this bogus? Need I be concerned? When I use the tool to reorder it screws
> up the tags!
The Acrobat "Touch Up Reading Order" tool is poorly named and the order
shown by the numbers in Acrobat can be misleading until you understand
that there is more than one "order" in a PDF.

The most important order in an accessible PDF is the tag order viewable
in the Tags pane. The Order pane does not show this order, but instead
shows the "Content" order which is based on how the content is actually
placed in the file.

Screenreaders use the Tag order. Adobe's built-in Read Aloud feature I
think uses the Content order.

To change the Tag order you simply move tags up and down the Tags pane.
To make the Content order match the Tags order, you can try moving
things around in the Order pane or directly in the Content pane itself.
However, your viewable content and your tags can easily get screwed up
if you use the Order pane to move things around, especially if you have
any tags nested inside other tags (like Spans or Figures inside P's
inside Article's).

The WebAIM site has a pretty good explanation of how to re-order a PDF
file here:
http://webaim.org/techniques/acrobat/acrobat#touchup

I like to think of the Content order as something like the "printing"
order, because if you start moving these items around you can end up
making some items disappear behind others, as though they have been
"printed" over by a non-transparent block of text or figure that appears
after them in the content order.

If forced to choose, always prioritize getting the tag order right
rather than the Order panel order.

> 2. I did indeed create 4 <article> sections but was unsure whether I
> should group the banner elements in some section or just list them as
> direct children of <document> ahead of the first <article>. My concern
> here is to use only well-supported HTML5 tags that will work with JAWS and
> other screen readers. Is the following structure OK?
> <Document>
> <Figure>
> <H1>
> <P>
> <Article>
> <Article>
>
> <Article>
>
> <Article>
>
Your structure looks okay to me!

Phil.