fix: HTML validation issues (#2814)

- Depreceated `summary` on tables
- Unopened STRONG and CODE tags
- Duplicate IDs
- Space in ID value

files/en-us/mdn/guidelines/css_style_guide/index.html

@@ -350,7 +350,7 @@ <h4 id="Style_notes">Style notes</h4>
 
 <h4 id="Example_syntax_18">Example syntax</h4>
 
-<pre class="brush: html">&lt;table class="standard-table" summary="This table details what tea we liked to drink back in the heady month of December 2015"&gt;
+<pre class="brush: html">&lt;table class="standard-table"&gt;
  &lt;caption&gt;Favorite teas, December 2015&lt;/caption&gt;
  &lt;thead&gt;
   &lt;tr&gt;

files/en-us/mozilla/firefox/releases/87/index.html

@@ -55,7 +55,7 @@ <h3 id="HTTP">HTTP</h3>
 
 <ul>
   <li>Some enterprise authentication services require that TLS client certificates be <a href="/en-US/docs/Web/HTTP/CORS#preflight_requests_and_credentials">sent in CORS preflight requests</a>. Users of these services can enable this (non-specification compliant) behavior using the <code>network.cors_preflight.allow_client_cert</code> preference ({{bug(1511151)}}).</li>
-  <li>The default <a href="/en-US/docs/Web/HTTP/Headers/Referrer-Policy">Referrer-Policy</a></code> has been changed to <code><a href="/en-US/docs/Web/HTTP/Headers/Referrer-Policy#strict-origin-when-cross-origin">strict-origin-when-cross-origin</a></code> (from <code>no-referrer-when-downgrade</code>), reducing the risk of leaking referrer information in cross-origin requests ({{bug(1589074)}}).</li>
+  <li>The default <code><a href="/en-US/docs/Web/HTTP/Headers/Referrer-Policy">Referrer-Policy</a></code> has been changed to <code><a href="/en-US/docs/Web/HTTP/Headers/Referrer-Policy#strict-origin-when-cross-origin">strict-origin-when-cross-origin</a></code> (from <code>no-referrer-when-downgrade</code>), reducing the risk of leaking referrer information in cross-origin requests ({{bug(1589074)}}).</li>
   <li><code><a href="/en-US/docs/Web/HTTP/Headers/Content-Length">Content-Length</a></code> has been added to the list of <a href="/en-US/docs/Glossary/CORS-safelisted_response_header">CORS-safelisted response headers</a> ({{bug(1460299)}}).</li>
 </ul>
 

files/en-us/web/api/eventtarget/addeventlistener/index.html

@@ -255,15 +255,15 @@ <h3 id="add_a_abortable_listener">Add an abortable listener</h3>
 
 <p>This example demonstrates how to add an <code>addEventListener()</code> that can be aborted with an {{domxref("AbortSignal")}}.</p>
 
-<h4 id="HTML">HTML</h4>
+<h4 id="HTML_5">HTML</h4>
 
 <pre class="brush: html">&lt;table id="outside"&gt;
   &lt;tr&gt;&lt;td id="t1"&gt;one&lt;/td&gt;&lt;/tr&gt;
   &lt;tr&gt;&lt;td id="t2"&gt;two&lt;/td&gt;&lt;/tr&gt;
 &lt;/table&gt;
 </pre>
 
-<h4 id="JavaScript">JavaScript</h4>
+<h4 id="JavaScript_5">JavaScript</h4>
 
 <pre class="brush: js">// Add an abortable event listener to table
 const controller = new AbortController();
@@ -285,7 +285,7 @@ <h4 id="JavaScript">JavaScript</h4>
 
 <p>In the above example just above, we modify the code in the previous example such that after the second row’s content changes to "three", we call <code>abort()</code> from the {{domxref("AbortController")}} we passed to the <code>addEventListener()</code> call. That results in the value remaining as "three" forever — because we no longer have any code listening for a click event.</p>
 
-<h4 id="Result">Result</h4>
+<h4 id="Result_5">Result</h4>
 
 <p>{{EmbedLiveSample('add_a_abortable_listener')}}</p>
 

files/en-us/web/api/fetch_api/using_fetch/index.html

@@ -25,7 +25,7 @@
 
 <ul>
  <li>The Promise returned from <code>fetch()</code> <strong>won’t reject on HTTP error status</strong> even if the response is an HTTP 404 or 500. Instead, it will resolve normally (with <code>ok</code> status set to false), and it will only reject on network failure or if anything prevented the request from completing.</li>
- <li><code>fetch()</code> won’t send cross-origin cookies</strong> unless you set the <em>credentials</em> <a href="/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch#parameters">init option</a>. (Since <a href="https://github.com/whatwg/fetch/pull/585" rel="nofollow noopener">April 2018</a>. The spec changed the default credentials policy to <code>same-origin</code>. Firefox changed since 61.0b13.)</li>
+ <li><code>fetch()</code> <strong>won’t send cross-origin cookies</strong> unless you set the <em>credentials</em> <a href="/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch#parameters">init option</a>. (Since <a href="https://github.com/whatwg/fetch/pull/585" rel="nofollow noopener">April 2018</a>. The spec changed the default credentials policy to <code>same-origin</code>. Firefox changed since 61.0b13.)</li>
 </ul>
 
 <p>A basic fetch request is really simple to set up. Have a look at the following code:</p>

files/en-us/web/html/element/hgroup/index.html

@@ -132,7 +132,7 @@ <h2 id="Specifications">Specifications</h2>
   </tbody>
 </table>
 
-<h2 id="Accessibility concerns">Accessibility concerns</h2>
+<h2 id="Accessibility_concerns">Accessibility concerns</h2>
 
 <p>The presence of <code>hgroup</code> may remove information reported to assistive technology about the subheading portion of the heading group.</p>
 

files/en-us/web/javascript/inheritance_and_the_prototype_chain/index.html

@@ -398,8 +398,8 @@ <h4 class="example">Code example</h4>
 console.log(inst.foo_prop);
 console.log(inst.bar_prop);
 </pre>
-<table class="standard-table" summary="Pros and cons of extending Object.prototype">
-  <caption>Pros and cons of exending Object.prototype</caption>
+<table class="standard-table">
+  <caption>Pros and cons of extending Object.prototype</caption>
 	<tbody>
     <tr>
       <th scope="row">Pro(s)</th>
@@ -412,8 +412,8 @@ <h4 class="example">Code example</h4>
       <p>Both of those are generally not problems in practice.</p>
       </td>
     </tr>
-    <tbody>
-    </table>
+  </tbody>
+</table>
 <h4 class="name">#2: {{jsxref("Object.create")}}</h4>
 <pre class="brush: js">
 // Technique 1
@@ -450,7 +450,7 @@ <h4 class="name">#2: {{jsxref("Object.create")}}</h4>
 var inst = new bar;
 console.log(inst.foo_prop);
 console.log(inst.bar_prop)</pre>
-<table class="standard-table" summary="Pros and cons of Object.create">
+<table class="standard-table">
   <caption>Pros and cons of {{jsxref("Object.create")}}</caption>
 	<tbody>
     <tr>
@@ -461,8 +461,8 @@ <h4 class="name">#2: {{jsxref("Object.create")}}</h4>
       <th scope="row">Con(s)</th>
       <td>Not supported in IE8 and below. However, as Microsoft has discontinued extended support for systems running IE8 and below, that should not be a concern for most applications. Additionally, the slow object initialization can be a performance black hole if using the second argument, because each object-descriptor property has its own separate descriptor object. When dealing with hundreds of thousands of object descriptors in the form of objects, that lag time might become a serious issue.</td>
     </tr>
-    <tbody>
-    </table>
+  </tbody>
+</table>
 <h4 class="example">#3: {{jsxref("Object.setPrototypeOf")}}</h4>
 <pre class="brush: js">
 // Technique 1
@@ -498,7 +498,7 @@ <h4 class="example">#3: {{jsxref("Object.setPrototypeOf")}}</h4>
 var inst = new bar;
 console.log(inst.foo_prop);
 console.log(inst.bar_prop)</pre>
-<table class="standard-table" summary="Pros and cons of Object.setPrototypeOf">
+<table class="standard-table">
   <caption>Pros and cons of {{jsxref("Object.setPrototypeOf")}}</caption>
 	<tbody>
     <tr>
@@ -509,8 +509,8 @@ <h4 class="example">#3: {{jsxref("Object.setPrototypeOf")}}</h4>
       <th scope="row">Con(s)</th>
       <td>Ill-performing. Should be deprecated. Many browsers optimize the prototype and try to guess the location of the method in memory when calling an instance in advance; but setting the prototype dynamically disrupts all those optimizations. It might cause some browsers to recompile your code for de-optimization, to make it work according to the specs. Not supported in IE8 and below.</td>
     </tr>
-    <tbody>
-    </table>
+  </tbody>
+</table>
 <h4 class="example">#4: Setting the {{jsxref("Object/proto","__proto__")}} property</h4>
 <pre id="example-4" class="brush: js">
 // Technique 1
@@ -541,7 +541,7 @@ <h4 class="example">#4: Setting the {{jsxref("Object/proto","__proto__")}} prope
 };
 console.log(inst.foo_prop);
 console.log(inst.bar_prop)</pre>
-			<table class="standard-table" summary="Pros and cons of setting the __proto__ property">
+			<table class="standard-table">
   <caption>Pros and cons of setting the {{jsxref("Object/proto","__proto__")}} property</caption>
 	<tbody>
     <tr>