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Merge pull request #2620 from w3c/fxl-a11y-issue-2618
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[FXLA11Y] Feedback from issue 2618
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@wareid
wareid authored May 22, 2024
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Expand Up @@ -65,7 +65,7 @@ <h3>Overview</h3>

<p>EPUB fixed layout publications, or publications where the print layout is preserved in the digital edition, have been around since before EPUB 3.0.1. These publications span a number of genres and types, from comic books, cook books, children's books, and more.</p>

<p>An accessible fixed layout EPUB file is one that meets the accessibility requirements of the Web Content Accessibility Guidelines 2.x level AA [[wcag2]] and EPUB Accessibility 1.1 [[epub-a11y-11]], including color contrast, reading order, font layout, structural navigation, metadata, and text alternatives. Not all WCAG success criteria are applicable to EPUB documents, a more detailed list can be found in <a href="#intro-principles">section 1.4</a>.</p>
<p>An accessible fixed layout EPUB file is one that meets the accessibility requirements of the Web Content Accessibility Guidelines 2.x level AA [[wcag2]] and EPUB Accessibility 1.1 [[epub-a11y-11]], including color contrast, reading order, font layout, structural navigation, accessibility metadata, and text alternatives. Not all WCAG success criteria are applicable to EPUB documents, a more detailed list can be found in <a href="#intro-principles">section 1.4</a>.</p>

<p>The main motivation behind creating fixed layout publications is the need to preserve the print layout of the book, either because of the layout's importance to the text (i.e. complex diagrams) or it's artistic purpose (i.e. illustrated text). These publications can often be partially or completely inaccessible to people with disabilities, especially disabilities affecting vision or visual processing. However, the visual nature of fixed layout publications can also offer advantages for disabled readers. Graphic and visual design is about much more than making things look pretty, and well-designed publications can create reading experiences that aid in increasing understanding, information retention, conveying complex ideas, and more.</p>

Expand Down Expand Up @@ -169,7 +169,7 @@ <h4>Robust</h4>
<p>These are the most applicable success criteria for fixed layout content:</p>

<ul>
<li><a href="https://www.w3.org/TR/WCAG22/#parsing">4.1.1 Parsing (note: this success criteria is no longer applicable in WCAG 2.2, but may remain important to EPUB rendering).</a></li>
<li><a href="https://www.w3.org/TR/WCAG22/#parsing">4.1.1 Parsing (note: this success criteria is no longer applicable in WCAG 2.2, but parsing errors are part of the checks done by <a href="https://www.w3.org/publishing/epubcheck/">EPUBCheck</a>).</a></li>
<li><a href="https://www.w3.org/TR/WCAG22/#name-role-value">4.1.2 Name, Role, Value (A)</a></li>
</ul>
</section>
Expand All @@ -184,7 +184,7 @@ <h3>Considerations for fixed layout content development</h3>

<p>EPUB 3.3 [[epub-33]] supports multiple methods for content development, particularly for fixed layout content. The two primary methods are to use XHTML and SVG for building EPUB content documents. A third method used in many EPUB fixed layout books is to reference image files in the spine of the EPUB file. We will discuss the accessibility considerations for all three methods in this document.</p>

<p>In addition to the core technologies mentioned in the EPUB 3.3 recommendation, EPUB accessibility may also require the use of the Accessible Rich Internet Applications [[wai-aria-1.2]] standard.</p>
<p>In addition to the core technologies mentioned in the EPUB 3.3 recommendation, EPUB accessibility may also require the use of the Accessible Rich Internet Applications [[wai-aria-1.2]] and Digital Publishing WAI-ARIA [[dpub-aria-1.1]] recommendations.</p>
</section>

<section id="reading-order">
Expand Down Expand Up @@ -417,7 +417,7 @@ <h4>Visual adjustments</h4>
<section id="legibility-visual">
<h4>Visual design</h4>

<p>Many of the Success Criteria mentioned previously focus on the content being programmatically available to the user (accessible to assistive technology), but the same principles that are communicated programmatically can also be communicated visually. For example, most content design makes a visual differentiation between heading and body text, as a visual indicator of their relationship. Programmatically, we use elements like <code>&lt;h1&gt;</code> and <code>&lt;p&gt;</code> to achieve this. Visually, we do this by styling headings with larger text, different colours, or a different font face.</p>
<p>Many of the Success Criteria mentioned previously focus on the content being programmatically available to the user (accessible to assistive technology), but the same principles that are communicated programmatically can also be communicated visually. For example, most content design makes a visual differentiation between heading and body text, as a visual indicator of their relationship. Programmatically, we use elements like <code>&lt;h1&gt;</code> and <code>&lt;p&gt;</code> to achieve this. Visually, we do this by styling headings with larger text, different colors, or a different font face.</p>

<p>Success Criteria like the following can be achieved with conscientious visual design:</p>

Expand Down Expand Up @@ -511,7 +511,7 @@ <h5>Font face</h5>

<p>Selecting a font face for your content can depend on a number of factors. When choosing a font for fixed layout content it is important for content creators to consider readability because a user will not be able to alter the font face to suit their needs or preferences.</p>

<p>One of the most important factors for the readability of fonts relates to character differentiation. Character differentiation in a font is a strong indicator of readability, specifically for characters that have similar shapes in a font face. In the Latin alphabet, letters like <strong>I</strong> and <strong>l</strong>, <strong>b</strong> and <strong>d</strong>, or <strong>a</strong> <strong>o</strong> and <strong>e</strong> can look very similar to one another depending on the style of the font. The same issue is possible in fonts for other alphabets, particularly when glyphs are similar in appearance or use similar elements. </p>
<p>One of the most important factors for the readability of fonts relates to character differentiation. Character differentiation in a font is a strong indicator of readability, specifically for characters that have similar shapes in a font face. In the Latin alphabet, letters like <strong>I</strong> (upper case "i") and <strong>l</strong> (lower case "l"), <strong>b</strong> and <strong>d</strong>, or <strong>a</strong> <strong>o</strong> and <strong>e</strong> can look very similar to one another depending on the style of the font. The same issue is possible in fonts for other alphabets, particularly when glyphs are similar in appearance or use similar elements. </p>
</section>
</section>
</section>
Expand Down Expand Up @@ -737,7 +737,7 @@ <h3>Accessibility metadata for a children's book with media overlays</h3>
&lt;meta property="schema:accessMode"&gt;textual&lt;/meta&gt;
&lt;meta property="schema:accessMode"&gt;auditory&lt;/meta&gt;
&lt;meta property="schema:accessModeSufficient"&gt;visual,textual,auditory&lt;/meta&gt;
&lt;meta property="schema:accessModeSufficient"&gt;textual&lt;/meta&gt;
&lt;meta property="schema:accessModeSufficient"&gt;textual, auditory&lt;/meta&gt;
&lt;meta property="schema:accessibilityFeature"&gt;alternativeText&lt;/meta&gt;
&lt;meta property="schema:accessibilityFeature"&gt;readingOrder&lt;/meta&gt;
&lt;meta property="schema:accessibilityFeature"&gt;synchronizedAudioText&lt;/meta&gt;
Expand All @@ -760,8 +760,10 @@ <h3>Accessibility metadata for a textbook with video</h3>
<pre>
&lt;meta property="schema:accessMode"&gt;visual&lt;/meta&gt;
&lt;meta property="schema:accessMode"&gt;textual&lt;/meta&gt;
&lt;meta property="schema:accessMode"&gt;auditory&lt;/meta&gt;
&lt;meta property="schema:accessModeSufficient"&gt;visual,textual&lt;/meta&gt;
&lt;meta property="schema:accessModeSufficient"&gt;textual&lt;/meta&gt;
&lt;meta property="schema:accessModeSufficient"&gt;visual,textual,auditory&lt;/meta&gt;
&lt;meta property="schema:accessModeSufficient"&gt;visual,auditory&lt;/meta&gt;
&lt;meta property="schema:accessibilityFeature"&gt;alternativeText&lt;/meta&gt;
&lt;meta property="schema:accessibilityFeature"&gt;readingOrder&lt;/meta&gt;
&lt;meta property="schema:accessibilityFeature"&gt;tableOfContents&lt;/meta&gt;
Expand Down Expand Up @@ -849,7 +851,7 @@ <h3>Reading system accessibility requirements</h3>
<li><a href="#rs-a11y-requirements-metadata">display the accessibility metadata provided in the EPUB;</a></li>
<li><a href="#rs-a11y-requirements-at">enable use of assistive technologies;</a></li>
<li><a href="#rs-a11y-requirements-nav">support EPUB navigation;</a></li>
<li><a href="#rs-a11y-requirements-resize">enable resizing a page up to 200 per cent;</a></li>
<li><a href="#rs-a11y-requirements-resize">enable resizing a page up to 200 percent;</a></li>
<li><a href="#rs-a11y-requirements-page">enable the display of an image full screen;</a></li>
<li><a href="#rs-a11y-requirements-alt">enable access to alternative text and extended descriptions;</a></li>
<li><a href="#rs-a11y-requirements-mo">support EPUB Media Overlays;</a></li>
Expand Down Expand Up @@ -901,7 +903,7 @@ <h4>Enable resizing a page</h4>

<ul>
<li><a href="https://www.w3.org/TR/WCAG22/#orientation">1.3.4 Orientation (AA)</a></li>
<li><a href="https://www.w3.org/TR/WCAG2/#resize-text">1.4.4 Resize Text (AA)</li>
<li><a href="https://www.w3.org/TR/WCAG2/#resize-text">1.4.4 Resize Text (AA)</a></li>
</ul>
</section>

Expand Down Expand Up @@ -958,6 +960,8 @@ <h3>Alternative rendering methods</h3>

<p>If the fixed layout publication does not conform to the recommendations made in this document, or WCAG [[wcag2]], providing alternate renderings of the content may result in an unusable or poor reading experience. Content that is not formatted in conformance with WCAG may result in output that has an incorrect reading order, broken sentences, or choppy pronounciation. The user should be informed if the content does not have accessibility metadata that would provide clarity on whether alternate renderings are supported, such as <code>dcterms:conformsTo</code> with a value for WCAG, or metadata values that conform to properties like <a href="https://w3c.github.io/publ-a11y/UX-Guide-Metadata/draft/principles/#supports-nonvisual-reading">Supports nonvisual reading</a> from the <a href="https://w3c.github.io/publ-a11y/UX-Guide-Metadata/draft/principles/">User Experience Guide for Displaying Accessibility Metadata</a>.</p>

<p class="ednote">The <a href="https://w3c.github.io/publ-a11y/UX-Guide-Metadata/draft/principles/">User Experience Guide for Displaying Accessibility Metadata</a> is currently a draft document and is subject to change.</p>

<p>There are ongoing discussions about transforming visual publications into reflowable textual content for complete AA compliance. While these are not in production yet, by creating our fixed layout with logical reading order, full image descriptions, and good semantics and structure where possible we are preparing our files in the best way for these future developments.</p>

<aside class="issue" title="Open issues regarding alternative rendering">
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