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h1. Accessibiliy Features

{{>toc}}

h2. Activate Accessibility Features

Add @a11y@ to the documentclass options:

<pre><code>\documentclass[…,a11y]{cocotex}

</code></pre>

For PDF 2.0 use @a11y20@, instead.

h2. Set main language

Add @lang-id=XXX@ to the documentclass options following "ISO 639-2":https://de.wikipedia.org/wiki/Liste_der_ISO-639-2-Codes, e.g. for German:

<pre><code>\documentclass[…,lang-id=deu]{cocotex}

</code></pre>

h2. Artifact tagging

Images and other contents that fulfill decorational purposes only must be tagged as artifacts to be ignored by reading software. This can be achieved as follows:

<pre><code class="tex">

\ccaStructStart{Artifact}Linie\ccaStructEnd{Artifact}

</code></pre>

* there exists also an environment that is not yet thoroughly tested:

<pre><code class="tex">

\begin{ccaArtifact}…\end{ccaArtifact}

</code></pre>

* consider tagging *decorational images*

* *writing lines* (if not tagged as forms)

* tbc

h2. Paragraph tagging

Until further notice, text paragraphs need to be tagged by the converter by adding @\ccaVstructStart{P}@ at the beginning of each paragraph (no whitespaces between the macro and subsequent text or other macros!) and @\ccaVstructEnd{P}@ at the end of each paragraph (no whitespaces before @\ccaVstructEnd@!):

<pre>

\ccaVstructStart{P}Ipsum Lorem … finis.\ccaVstructEnd{P}

</pre>

This must also be done in broader contexts that may(!) contain multiple paragraphs of plain text, like footnotes, captions, list items, quotations, table cells or abstracts. Which ones exactly varies from publisher style to publisher style, so if in doubt, ask your friendly neighborhood TeX developer.

h2. Alternative Texts

Figures and Math both need alternative texts.

h4. Figures

For figures, there are two ways to encode alt-text: the @alt@ Parameter in the optional argument of @\includegraphics@ (needs texlive > 2021), e.g.

<pre>\incudegraphics[...,alt={This is what the image file shows}]{image.png}</pre>

or as @\tpAltText@ inside the @tpFigure@ or @tpSubFloat@ environments:

<pre>\begin{tpFigure}

  \tpCaption{This is the caption}

  \tpAltText{This is the alt text. It MUST NOT be the same as the caption!}

  \tpFig{\includegraphics{image.png}}

\end{tpFigure}</pre>If both exist, the @alt@ in @\includegraphics@ takes precedence over the @\tpAltText@.

h4. Math

both inline and display style math needs alternative texts. This is done with the @\ccaAddAltText@ macro:

<pre>

\begin{equation*}\ccaAddAltText{Z equals x minus mu divided by sigma}%

  \mathbf{Z}=\,\frac{\boldsymbol{x}-\mathbf{\mu }}{\mathbf{\sigma }}

\end{equation*}

</pre>

or, for inline math:

<pre>The Variable $x\addAltText{x}$ means...</pre>

h2. XMP Meta Data

* ***"Template.xmp":https://redmine.le-tex.de/attachments/27865***

PDF/UA requires meta data to be embedded into the PDF file. CoCoTeX provides two ways to do that: If the TeX run does not find a xmp file that has the same basename as the .tex document, it generates one from the data in the tpMeta environment. If there is a .xmp file (either because it was there from the beginning, or it was generated during a previous tex run), it includes that one. If the xmp file is to be generated by the converter, make sure to use the "attached template.xmp":https://redmine.le-tex.de/attachments/27865 (see below) and include the document specific meta data in line 24 instead of the comment.

***Important: Don't remove anything in that template, especially not the PIs at the beginning and end, and the blank spaces at the bottom of the template!***

Also be cautious where to use @rdf:Bag@, @rdf:Alt@ and @rdf:Seq@!

Use the following XML tags for meta data:

h4. Author

is a list of the document's main authors or edtiors, one per line:

<pre><code class="xml">

<dc:creator>

  <rdf:Seq>

    <rdf:li>Firstname Lastname</rdf:li>

    <rdf:li>Firstname Lastname</rdf:li>

    ...

  </rdf:Seq>

</dc:creator>

</code></pre>

h4. Document Title

There can be more than one document title for various languages. The displayed title (e.g. in the pdf viewer window's top line) depends on the selected system language

<pre><code class="xml">

<dc:title>

  <rdf:Alt>

    <rdf:li xml:lang="x-default">Default title</rdf:li>

  </rdf:Alt>

</dc:title>

</code></pre>

h4. Publisher

<pre><code class="xml">

<dc:publisher>

  <rdf:Bag>

    <rdf:li>Publisher Name</rdf:li>

  </rdf:Bag>

</dc:publisher>

</code></pre>

h4. Chapter authors/Contributors

<pre><code class="xml">

<dc:contributor>

  <rdf:Bag>

    <rdf:li>Firstname Lastname</rdf:li>

    <rdf:li>Firstname Midname Lastname</rdf:li>

    ...

  </rdf:Bag>

</dc:contributor>

</code></pre>

h4. Abstract

Like @dc:title@, @dc:description@ allows multiple entries for different languages.

<pre><code class="xml">

<dc:description>

  <rdf:Alt>

    <rdf:li xml:lang="x-default">...</rdf:li>

  </rdf:Alt>

</dc:description>

</code></pre>

h4. Keywords

<pre><code class="xml">

<dc:subject>

  <rdf:Bag>

    <rdf:li>keyword 1</rdf:li>

    <rdf:li>keyword 2</rdf:li>

    ....

  </rdf:Bag>

</dc:subject>

</code></pre>

h4. Copyright

<pre><code class="xml">

<dc:rights>

  <rdf:Alt>

    <rdf:li xml:lang="x-default">Unless otherwise indicated, this work is licensed under a Creative Commons License Attribution 4.0 International. This does not apply to quoted content and works based on other permissions.</rdf:li>

  </rdf:Alt>

</dc:rights>

</code></pre>

h4. Other

If you must, you can _alter_ the values of @<pdf:Producer>@ and @<xmp:CreatorTool>@, where @pdf:Producer@ is the tool that generated the PDF, and @xmp:CreatorTool@ is the Tool with which the original manuscript was created prior to any conversions or transformations.

The values of @xmp:ModifyDate@ and @xmp:CreateDate@ are generated and overwritten during the tex run by the ltpdfa package, so you can leave those fields as they are.

h2. Colours and Embedded Images

h3. Output Intent and Embedded ICC Colour Profiles

By default, CoCoTeX puts **CMYK** as output intent, but this can be overridden with the @color-env@ class option:

<pre><code class="latex">\documentclass[…,color-env=<space>,…]{cocotex}</code></pre>The Value @<space>@ should be one of the values in the left column of the following table:

|_. @<space>@ |_. icc profile|

| @srgb@, @rgb@ |  IEC 61966-2.1 Default RGB colour space - sRGB |

| @cmy@, @cmyk@ | Coated FOGRA39 |

| @grey@, @gray@ | ISO Coated v2 - GREY 1c - (basICColor) |

| @natural@, @none@ | (gray) |

Publisher-wide colour profile can be set with the @profile@ Property of the @titlepage@ Container:<pre><code class="latex">\ccAddToType{Properties}{titlepage}{%

    \ccSetProperty{output-intent}{%

      profile=<path to .icc file>;%

      components=<number of colour components>;%

      identifier=<name of colour profile>%

  }}</code></pre>with the following values:

* @<path to .icc file>@ is the path to the icc colour profile relative to the .tex file, including the file extension.

* @<number of colour components>@ is the number of colour components, e.g., @3@ for RGB, @4@ for CMYK, etc.

* @<name of colour profile>@ is the name of the colour profile (default values correspond to the right column in above's table)

A custom .icc profile valid only for the current document can be embedded with the following Components inside the @tpMeta@ environment:<pre><code class="latex">\begin{tpMeta}

  …

  \tpIccProfileFile{<path to .icc file>}

  \tpIccComponents{<number of colour components>}

  \tpIccIdentifier{<name of colour profile>}

  …

\end{tpMeta}</code></pre>

h3. Image files

The colour spaces of embedded images **must match the Output Indent of the PDF file** for the latter to be PDF/A2-a compatible. 

A quick-and-dirty conversion can be done with imagemagick:<pre><code class="bash">magick <input>  -colorspace <color_space> -profile <path_to_icc> <output></code></pre>with

* @<input>@ the path to the input image

* @<color_space>@ the color space the image should be converted to (cmyk, rgb, etc)

* @<path_to_icc>@ the path to the icc profile that gets embedded into the image

* @<output>@ the name of the output image

h3. Custom Text Colours

Custom document colours get automatically converted to the Output Intent color space by LaTeX, so they may be defined with any color model. The following colour definitions are roughly equivalent:<pre><code class="latex">\definecolor{myblue}{HTML}{3527FF}

\definecolor{myblue}{RGB}{53,39,255}

\definecolor{myblue}{rgb}{0.21,0.15,1}

\definecolor{myblue}{cmyk}{0.79,0.85,0,0}</code></pre>

h2. Checking PDF/UA compliance on Linux

The main tool for validating the PDF/UA compliance of documents is the "PDF Accessibility Checker (PAC)":https://support.axes4.com/hc/de/articles/7371921627794-PDF-Accessibility-Checker-PAC-2024. Using it on Windows is rather straightforward but requires a few more steps to make it run on Linux. The following procedure has been tested successfully with Wine 7.0 and should work with later versions quite as well.

# Install <code>wine</code> and <code>winetricks</code> via your package manager. Ensure that it is at least Wine version 7.0.

# It is recommended to use a separate Wine prefix (i.e. a separate environment with its own configuration and installed Windows components/packages). To do so, issue <code>WINEPREFIX=~/.wine-pac wineboot --init</code>. The path <code>~/.wine_pac</code> is an example and may be replaced with a path to your liking.

# Install all fonts available for Wine (<code>corefonts</code> package won’t suffice) as well as .NET 4.8 by issuing <code>WINEPREFIX=~/.wine-pac winetricks --force dotnet48 allfonts</code>. The <code>--force</code> option is required, because <code>winetricks</code> will otherwise quit the installation with a warning, stating that the .NET 4.8 package may be broken since Wine release 5.0.

# After the installation routines of the aforementioned Windows software via Wine, you should now be able to run PAC via <code>WINEPREFIX=~/.wine-pac wine "/Path/to/your/PAC_directory/PAC.exe".