Re: How to get tagging off in new LaTeX

On Sun, 2 Nov 2025 at 19:28, Bruno Voisin via tex-live <[email protected]>
wrote:

> That's not a TL-specific question, but I assume some other users here may
> wonder the same.
>
> Yesterday's TUG news mentioned yesterday's LaTeX news (issue 42) which
> describes yesterday's new LaTeX release (2025-11-01). This new release is
> already in the TeX Live updates.
>
> The first three pages of LT news describe the extensive changes to the
> tagging behaviour, which is now triggered by \DocumentMetadata{}. Reaching
> the second column of page 2 of the news, I was already lost (so many new
> tagging-related packages, keys, commands, behaviours), and my only concern
> henceforth has been: how can I make sure the new tagging feature is
> completely off for now -- until I get a better hold of what tagging is and
> brings, and how it works in LaTeX -- while still keeping the other benefits
> of \DocumentMetadata{}?
>
> I appreciate getting PDF 2.0 by default, and T1 fonts, and the
> pdfmanagement niceties like
>
> \ExplSyntaxOn
>
> \AddToHook{env/sidewaysfigure/end}{\pdfmanagement_add:nnn{ThisPage}{Rotate}{90}}
>
> \AddToHook{env/sidewaystable/end}{\pdfmanagement_add:nnn{ThisPage}{Rotate}{90}}
> \ExplSyntaxOff
>
> to automatically rotate pages containing sideways figures or tables. But I
> fear that tagging might break the journal packages (like REVTeX, but also
> others) that I need to use most of the time.
>

This is not tagging in the sense of tagged PDF, and as you note below the
pdfmanagent features can be loaded separately if required.

>
> The LaTeX news are a bit unclear in this respect. Reading them, I have the
> impression \DocumentMetadata{}, without any argument, does trigger tagging.


No, in the new release  \DocumentMetadata{} is essentially
\DocumentMetadata{tagging=off} so it does load new template code and other
things but does not trigger the generation of tagged PDF.


> But then there is "[\DocumentMetadata] will now load directly all the code
> that one would get when using the tagging=off or the testphase=latest key",
> which gives the impression tagging won't be loaded ("tagging=off" means no
> tagging, right?).
>

Exactly.

>
> So, in essence, my question is: how to de-activate tagging while keeping
> everything else \DocumentMetadata provides (PDF 2.0, T1 fonts and
> pdfmanagement)? Is this
>
> \DocumentMetadata{tagging=off}
>
> Or
>
> \RequirePackage{pdfmanagement}
> \SetKeys[document/metadata]{pdfversion=2.0}
>
> plus something else for T1 fonts?
>

the "something else" would be \usepackage[T1]{fontenc}

You can use either. The first form with \DocumentMetadata loads the code
(currently mostly in latex-lab) that re-implements many parts of latex with
the template key-value system, this sets things up to enable tagging but
tagging is not enabled, but the templates have other uses as well providing
features such as key=value lists similar to the well known enumitem package.

Packages can detect the use of "new" documents that have \DocumentMetadata
with \IfDocumentMetadatTF{...}{...}  so for most
purposes if you want to opt in to the new code at all I would use that form
but if you have compatibility reasons for not loading the latex lab code
you can still load just pdfmanagement as you show.



> Also, I wasn't aware \DocumentMetadata{} before meant an alternative
> hyperref driver was used (LT news, bottom of page 1, column 2). I use to
> customize hyperref output at times, copying pieces of code from the drivers
> in tex/latex/hyperref (like hpdftex.def) and putting a modified version in
> the preamble of my document. If I get things right, another hyperref driver
> file is involved when \DocumentMetadata{} is used, from another location.
> Where should I look then? Are the hyperref changes scattered in the various
> files inside tex/latex/latex-lab/?
>

see pdfresources/hyperref-generic.dtx

>
> Bruno Voisin
>
>
>
David