🔧 main: work in progress [might break]

doc/RFC_XR_Fragments.html

@@ -1453,13 +1453,21 @@ Instead, it encourages browsers to scan nodes for the following custom propertie
 <ul>
 <li><a href="https://spdx.dev/">SPDX</a> license information</li>
 <li><a href="https://www.w3.org/WAI/standards-guidelines/aria/">ARIA</a> attributes (<code>aria-*: .....</code>)</li>
+</ul>
+
+<blockquote>
+<p>SPDX and ARIA&rsquo;s <code>aria-description</code> are normative, as they promote accessibility and scene transcripts: please start <code>aria-description</code> with a verb to aid transcripts.</p>
+</blockquote>
+
+<p>The following metadata are non-normative but encouraged, since they are popular and cheap to parse:</p>
+
+<ul>
+<li><a href="https://json-ld.org">RDF/JSON-LD</a> like <a href="https://mvmd.org/standards/gltf/">this example</a> or via glTF&rsquo;s <a href="https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_xmp_json_ld">KHR_xmp_json_ld extension</a></li>
 <li><a href="https://ogp.me">Open Graph</a> attributes (<code>og:*: .....</code>)</li>
 <li><a href="https://www.dublincore.org/specifications/dublin-core/application-profile-guidelines/">Dublin-Core</a> attributes(<code>dc:*: .....</code>)</li>
 <li><a href="https://bibtex.eu/fields">BibTex</a> when known bibtex-keys exist with values enclosed in <code>{</code> and <code>},</code></li>
 </ul>
 
-<p><strong>ARIA</strong> (<code>aria-description</code>) is the most important to support, as it promotes accessibility and allows scene transcripts. Please start <code>aria-description</code> with a verb to aid transcripts.</p>
-
 <blockquote>
 <p>Example: object &lsquo;tryceratops&rsquo; with <code>aria-description: is a huge dinosaurus standing on a #mountain</code> generates transcript <code>#tryceratops is a huge dinosaurus standing on a #mountain</code>, where the hashtags are clickable XR Fragments (activating the visible-links in the XR browser).</p>
 </blockquote>
@@ -1526,7 +1534,7 @@ Instead, it encourages browsers to scan nodes for the following custom propertie
 <p>* = these are interchangable (only one needs to be defined)</p>
 </blockquote>
 
-<p>There&rsquo;s no silver bullet when it comes to metadata, so one should support where the metadata is/goes.</p>
+<p>There&rsquo;s no silver bullet when it comes to metadata, so XR Fragment-implementations should support where the metadata is/goes.</p>
 
 <blockquote>
 <p>These attributes can be scanned and presented during an <code>href</code> or <code>src</code> eye/mouse-over.</p>

doc/RFC_XR_Fragments.md

@@ -956,11 +956,16 @@ Instead, it encourages browsers to scan nodes for the following custom propertie
 
 * [SPDX](https://spdx.dev/) license information
 * [ARIA](https://www.w3.org/WAI/standards-guidelines/aria/) attributes (`aria-*: .....`)
+
+> SPDX and ARIA's `aria-description` are normative, as they promote accessibility and scene transcripts: please start `aria-description` with a verb to aid transcripts. 
+
+The following metadata are non-normative but encouraged, since they are popular and cheap to parse:
+
+* [RDF/JSON-LD](https://json-ld.org) like [this example](https://mvmd.org/standards/gltf/) or via glTF's [KHR_xmp_json_ld extension](https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_xmp_json_ld)
 * [Open Graph](https://ogp.me) attributes (`og:*: .....`)
 * [Dublin-Core](https://www.dublincore.org/specifications/dublin-core/application-profile-guidelines/) attributes(`dc:*: .....`)
 * [BibTex](https://bibtex.eu/fields) when known bibtex-keys exist with values enclosed in `{` and `},`
 
-**ARIA** (`aria-description`) is the most important to support, as it promotes accessibility and allows scene transcripts. Please start `aria-description` with a verb to aid transcripts. 
 
 > Example: object 'tryceratops' with `aria-description: is a huge dinosaurus standing on a #mountain` generates transcript `#tryceratops is a huge dinosaurus standing on a #mountain`, where the hashtags are clickable XR Fragments (activating the visible-links in the XR browser).
 
@@ -980,7 +985,7 @@ Individual nodes can be enriched with such metadata, but most importantly the sc
 
 > \* = these are interchangable (only one needs to be defined)
 
-There's no silver bullet when it comes to metadata, so one should support where the metadata is/goes.
+There's no silver bullet when it comes to metadata, so XR Fragment-implementations should support where the metadata is/goes.
 
 > These attributes can be scanned and presented during an `href` or `src` eye/mouse-over.
 

doc/RFC_XR_Fragments.xml

@@ -1295,11 +1295,16 @@ Instead, it encourages browsers to scan nodes for the following custom propertie
 <ul spacing="compact">
 <li><eref target="https://spdx.dev/">SPDX</eref> license information</li>
 <li><eref target="https://www.w3.org/WAI/standards-guidelines/aria/">ARIA</eref> attributes (<tt>aria-*: .....</tt>)</li>
+</ul>
+<blockquote><t>SPDX and ARIA's <tt>aria-description</tt> are normative, as they promote accessibility and scene transcripts: please start <tt>aria-description</tt> with a verb to aid transcripts.</t>
+</blockquote><t>The following metadata are non-normative but encouraged, since they are popular and cheap to parse:</t>
+
+<ul spacing="compact">
+<li><eref target="https://json-ld.org">RDF/JSON-LD</eref> like <eref target="https://mvmd.org/standards/gltf/">this example</eref> or via glTF's <eref target="https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_xmp_json_ld">KHR_xmp_json_ld extension</eref></li>
 <li><eref target="https://ogp.me">Open Graph</eref> attributes (<tt>og:*: .....</tt>)</li>
 <li><eref target="https://www.dublincore.org/specifications/dublin-core/application-profile-guidelines/">Dublin-Core</eref> attributes(<tt>dc:*: .....</tt>)</li>
 <li><eref target="https://bibtex.eu/fields">BibTex</eref> when known bibtex-keys exist with values enclosed in <tt>{</tt> and <tt>},</tt></li>
 </ul>
-<t><strong>ARIA</strong> (<tt>aria-description</tt>) is the most important to support, as it promotes accessibility and allows scene transcripts. Please start <tt>aria-description</tt> with a verb to aid transcripts.</t>
 <blockquote><t>Example: object 'tryceratops' with <tt>aria-description: is a huge dinosaurus standing on a #mountain</tt> generates transcript <tt>#tryceratops is a huge dinosaurus standing on a #mountain</tt>, where the hashtags are clickable XR Fragments (activating the visible-links in the XR browser).</t>
 </blockquote><t>Individual nodes can be enriched with such metadata, but most importantly the scene node:</t>
 <table>
@@ -1357,7 +1362,7 @@ Instead, it encourages browsers to scan nodes for the following custom propertie
 </tr>
 </tbody>
 </table><blockquote><t>* = these are interchangable (only one needs to be defined)</t>
-</blockquote><t>There's no silver bullet when it comes to metadata, so one should support where the metadata is/goes.</t>
+</blockquote><t>There's no silver bullet when it comes to metadata, so XR Fragment-implementations should support where the metadata is/goes.</t>
 <blockquote><t>These attributes can be scanned and presented during an <tt>href</tt> or <tt>src</tt> eye/mouse-over.</t>
 </blockquote></section>
 

doc/shell.nix

@@ -6,6 +6,7 @@
 
       mmark
       xml2rfc
+      python312Packages.lxml
       wkhtmltopdf-bin
       imagemagick