Hi Karljūrgen,

On 17/03/2019, at 1:42, "Karljürgen Feuerherm" <kfeuerh...@kfeuerherm.ca> wrote:

> Ross,
> 
> Your reply caught my eye, and I am now looking at the pdfx package 
> documentation.
> 
> May I ask, if accessibility is a concern, why a-2b/-2u rather than -ua-1, 
> which seems directly targeted at this?

PDF/UA and PDF/A-1a,2a,3a  require a fully tagged PDF.
This is a highly non-trivial task, which requires adding much extra to the 
document, done almost entirely through \special commands. The pdfx package does 
not provide this, but is useful for meeting the Metadata and other requirements 
of these formats.

Abstractly, accessibility is about having sufficient information stored in the 
PDF for software tools to be able to build and present a description of the 
content and structure, other than the visual one. The same can be said of 
software for converting into a different format.

A significant part of this is being able to correctly identify each character 
in the fonts used within the TeX/produced PDF. Even this is a non-trivial 
problem, due to TeX's non-standard font encodings, and virtual font technique.

> 
> Many thanks,
> 
> K
> 
>> You should use the  pdfx  package and prepare for  PDF/A-2b or -2u.
>> This fixes many of these things that affect conversions, as well as 
>> Accessibility and Archivability.
>> 
>> It's not fully tagged PDF, but handles many other technical issues.
>> 


Hope this helps.

Ross

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