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Re: Z-Order and Tag Order Need to Match?

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From: L Snider
Date: May 27, 2020 3:12PM

What I have been wondering since Acrobat came out with the Z-Order and Tags
in the dark ages, why the heck are they still separate in 2020? Can someone
enlighten me on why PDFs have to have so many layers, and why they can't be
converted to one layer...so we just remediate one layer? I am getting
increasingly frustrated with tech from the 2000s...

Cheers

Lisa

On Wed, May 27, 2020 at 3:36 PM Paul Rayius < <EMAIL REMOVED> > wrote:

> Hi Ilana,
> There's often a lot of question/ debate about this. When it comes to PDF
> standards (both ISO 32000 and PDF/UA, as well as WCAG 2.0 and 2.1) they're
> all quite clear that the reading order in a PDF shall be determined by the
> order of the tags. (To be more clear, WCAG doesn't specify the reading
> order "rules" for PDF but does provide some guidance in the WCAG
> Techniques.)
>
> The confusion comes into play because some assistive technologies don't
> actually follow the standards and so they'll read content from "other
> areas" in a PDF - for example from the Content and or "Z-Order" pane in
> Acrobat. (The "Z-Order" pane is the one labeled "Order" but many people
> call it the "Z-Order" because of the "Z" in the icon.)
>
> The problem, however, is that as accessible document creators and/or
> remediators, we can't possibly be called on to remediate according to how a
> particular processor or AT will handle a PDF. In fact, to that point, one
> of the great things about WCAG is that it's intended for accessibility
> while being technology independent. Personally, I think it's time for PDF
> processors and AT developers to be held accountable and that their products
> should adhere to the standards that are not only available but also
> achievable. But, that's my soapbox.
>
> I hope this helps to clarify, though, that the reading order in a PDF is
> to be determined by the order of the Tags and not the "Z-Order."
>
> Best,
> Paul
>
> Paul Rayius
> Director of Training
> CommonLook
>
>