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

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From: Paul Rayius
Date: May 27, 2020 4:36PM

Hi Michael,
As I just replied to another post on this thread, As per ISO 32000, one of the intents of PDF is that the "accessible layer" and the visual layer are independent of each other. (Apparently there are multiple strings going on at the same time!)
Among the benefits of this is that it's possible to add attributes (like Alternative text) and to change the reading order in the Tags without effecting the physical appearance of the document. Meanwhile, moving things around in the Content can (and often does) change how the document looks.

It was a design decision by our developers to make CommonLook so that the Content panel isn't changed when remediating a PDF. In fact, in a (much) older version of CommonLook PDF, we used to have the "merged view" which did change the order of things in the Tags and the Content at the same time but people had to be really careful or else they could change how the document looked visually. We did away with that about 5 years ago.

I hope that explanation helps.

Paul Rayius
Director of Training
CommonLook