title: Why does this GET for favicon.ico fire and fail if my HTML5 passes validation?
body: <p>I have the following HTML page as a test:</p>
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html lang=&quot;en&quot;&gt;
      &lt;head&gt;
          &lt;title&gt;Best Title Ever!&lt;/title&gt;
          &lt;meta charset=&quot;utf-8&quot;&gt;
      &lt;/head&gt;
      &lt;body&gt;
          &lt;p&gt;Finally, some content.&lt;/p&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  <p>If I test that HTML at the <a href="https://validator.w3.org/nu/#textarea" rel="nofollow noreferrer">W3 Validator</a> it will state :</p>
  <blockquote>
  <p>Document checking completed. No errors or warnings to show.</p>
  </blockquote>
  <p>Even though there are no errors when the page is served from Node's http-server I see (in the console) the following warning or error when the page is retrieved:</p>
  <pre><code>[2020-10-28T13:10:48.760Z]  &quot;GET /favicon.ico&quot; Error (404): &quot;Not found&quot;
  </code></pre>
  <p>You can also see the error in the Chrome or FireFox console which looks like:</p>
  <p>FireFox ==&gt; <code>GET http://127.0.0.1:8003/favicon.ico [HTTP/1.1 404 Not Found 2ms</code></p>
  <p>Chrome ==&gt; <code>Failed to load resource: favicon.ico:1 the server responded with a status of 404 (Not Found)</code></p>
  <p>What is attempting to retrieve that icon?</p>
  <p><strong>Things I've Tried</strong></p>
  <p>I've attempted to retrieve this from:</p>
  <ol>
  <li>FireFox - 82.0 64-bit</li>
  <li>Chrome - Version 86.0.4240.111 (Official Build) (64-bit)</li>
  </ol>
  <p>Is this error not correct?</p>
  <p><strong>How Do I Resolve This?</strong>
  Is it a requirement that a favicon.ico is always set with*</p>
  <pre><code>&lt;link rel=&quot;icon&quot; 
        type=&quot;image/png&quot; 
        href=&quot;http://example.com/myicon.png&quot;&gt;
  </code></pre>
  <p>*From <a href="https://www.w3.org/2005/10/howto-favicon" rel="nofollow noreferrer">https://www.w3.org/2005/10/howto-favicon</a></p>
  <p><strong>Adding that does indeed resolve the issue</strong> (the failed GET is no longer displayed), even though the png link doesn't even exist.</p>
  <p>If it is a requirement then why doesn't the W3 validator warn me to add it?</p>
  <p>Is that a bug in the W3 Validator?</p>