Add custom footer with RFC8174 conformance.

Fixes #468.

footer.include

@@ -0,0 +1,166 @@
+</main>
+<div data-fill-with="conformance">
+    <h2 id="conformance" class="no-ref no-num">
+    Conformance</h2>
+
+        <p>
+           The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
+           NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED",
+           "MAY", and "OPTIONAL" in this document are to be interpreted as
+           described in BCP 14 [[!RFC2119]] [[!RFC8174]] when, and only when, they
+           appear in all capitals, as shown here.
+
+        <p>
+            All of the text of this specification is normative
+            except sections explicitly marked as non-normative, examples, and notes. [[!RFC2119]]
+
+        <p>
+            Examples in this specification are introduced with the words “for example”
+            or are set apart from the normative text with <code nohighlight>class="example"</code>, like this:
+
+        <div class="example" id="example-example">
+            This is an example of an informative example.
+        </div>
+
+        <p>
+            Informative notes begin with the word “Note”
+            and are set apart from the normative text with <code nohighlight>class="note"</code>, like this:
+
+        <p class='note'>
+            Note, this is an informative note.</p>
+
+        <wpt title="Tests relating to the content of this specification
+                    may be documented in “Tests” blocks.
+                    Any such block is non-normative."></wpt>
+</div>
+</body>
+<script>
+(function() {
+  "use strict";
+  var collapseSidebarText = '<span aria-hidden="true">←</span> '
+                          + '<span>Collapse Sidebar</span>';
+  var expandSidebarText   = '<span aria-hidden="true">→</span> '
+                          + '<span>Pop Out Sidebar</span>';
+  var tocJumpText         = '<span aria-hidden="true">↑</span> '
+                          + '<span>Jump to Table of Contents</span>';
+
+  var sidebarMedia = window.matchMedia('screen and (min-width: 78em)');
+  var autoToggle   = function(e){ toggleSidebar(e.matches) };
+  if(sidebarMedia.addListener) {
+    sidebarMedia.addListener(autoToggle);
+  }
+
+  function toggleSidebar(on) {
+    if (on == undefined) {
+      on = !document.body.classList.contains('toc-sidebar');
+    }
+
+    /* Don't scroll to compensate for the ToC if we're above it already. */
+    var headY = 0;
+    var head = document.querySelector('.head');
+    if (head) {
+      // terrible approx of "top of ToC"
+      headY += head.offsetTop + head.offsetHeight;
+    }
+    var skipScroll = window.scrollY < headY;
+
+    var toggle = document.getElementById('toc-toggle');
+    var tocNav = document.getElementById('toc');
+    if (on) {
+      var tocHeight = tocNav.offsetHeight;
+      document.body.classList.add('toc-sidebar');
+      document.body.classList.remove('toc-inline');
+      toggle.innerHTML = collapseSidebarText;
+      if (!skipScroll) {
+        window.scrollBy(0, 0 - tocHeight);
+      }
+      tocNav.focus();
+      sidebarMedia.addListener(autoToggle); // auto-collapse when out of room
+    }
+    else {
+      document.body.classList.add('toc-inline');
+      document.body.classList.remove('toc-sidebar');
+      toggle.innerHTML = expandSidebarText;
+      if (!skipScroll) {
+        window.scrollBy(0, tocNav.offsetHeight);
+      }
+      if (toggle.matches(':hover')) {
+        /* Unfocus button when not using keyboard navigation,
+           because I don't know where else to send the focus. */
+        toggle.blur();
+      }
+    }
+  }
+
+  function createSidebarToggle() {
+    /* Create the sidebar toggle in JS; it shouldn't exist when JS is off. */
+    var toggle = document.createElement('a');
+      /* This should probably be a button, but appearance isn't standards-track.*/
+    toggle.id = 'toc-toggle';
+    toggle.class = 'toc-toggle';
+    toggle.href = '#toc';
+    toggle.innerHTML = collapseSidebarText;
+
+    sidebarMedia.addListener(autoToggle);
+    var toggler = function(e) {
+      e.preventDefault();
+      sidebarMedia.removeListener(autoToggle); // persist explicit off states
+      toggleSidebar();
+      return false;
+    }
+    toggle.addEventListener('click', toggler, false);
+
+
+    /* Get <nav id=toc-nav>, or make it if we don't have one. */
+    var tocNav = document.getElementById('toc-nav');
+    if (!tocNav) {
+      tocNav = document.createElement('p');
+      tocNav.id = 'toc-nav';
+      /* Prepend for better keyboard navigation */
+      document.body.insertBefore(tocNav, document.body.firstChild);
+    }
+    /* While we're at it, make sure we have a Jump to Toc link. */
+    var tocJump = document.getElementById('toc-jump');
+    if (!tocJump) {
+      tocJump = document.createElement('a');
+      tocJump.id = 'toc-jump';
+      tocJump.href = '#toc';
+      tocJump.innerHTML = tocJumpText;
+      tocNav.appendChild(tocJump);
+    }
+
+    tocNav.appendChild(toggle);
+  }
+
+  var toc = document.getElementById('toc');
+  if (toc) {
+    createSidebarToggle();
+    toggleSidebar(sidebarMedia.matches);
+
+    /* If the sidebar has been manually opened and is currently overlaying the text
+       (window too small for the MQ to add the margin to body),
+       then auto-close the sidebar once you click on something in there. */
+    toc.addEventListener('click', function(e) {
+      if(e.target.tagName.toLowerCase() == "a" && document.body.classList.contains('toc-sidebar') && !sidebarMedia.matches) {
+        toggleSidebar(false);
+      }
+    }, false);
+  }
+  else {
+    console.warn("Can't find Table of Contents. Please use <nav id='toc'> around the ToC.");
+  }
+
+  /* Wrap tables in case they overflow */
+  var tables = document.querySelectorAll(':not(.overlarge) > table.data, :not(.overlarge) > table.index');
+  var numTables = tables.length;
+  for (var i = 0; i < numTables; i++) {
+    var table = tables[i];
+    var wrapper = document.createElement('div');
+    wrapper.className = 'overlarge';
+    table.parentNode.insertBefore(wrapper, table);
+    wrapper.appendChild(table);
+  }
+
+})();
+</script>
+</html>

index.bs

@@ -9,6 +9,7 @@ Shortname: iamf
 URL: https://aomediacodec.github.io/iamf/
 Date: 2023-07-10
 Abstract: This document specifies an immersive audio (IA) model, a standalone IA sequence format and an [[!ISOBMFF]]-based IA container format.
+Local Boilerplate: footer yes
 </pre>
 
 <pre class="anchors">
@@ -93,6 +94,9 @@ url: https://tools.ietf.org/html/rfc7845#; spec: RFC7845; type: dfn;
 url: https://tools.ietf.org/html/rfc6716#; spec: RFC6716; type: dfn;
 	text: opus packet
 
+url: https://tools.ietf.org/html/rfc8174#; spec: RFC8174; type: property;
+	text:
+
 url: https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1770-4-201510-I!!PDF-E.pdf#; spec: ITU1770-4; type: dfn;
 	text: LKFS