title: how many `<main>` main tag can be used in a html document / Page
body: <p>how many main tags can be added to my html page. Is there any restriction to add more than one main tag(like one  per page)? </p>
  
  <p>is this correct way of using main tag??</p>
  
  <pre><code>&lt;body&gt;
    &lt;header&gt;&lt;/header&gt;
    &lt;aside&gt;&lt;/aside&gt;
    &lt;main&gt;
      &lt;section&gt;&lt;/section&gt;
      &lt;main&gt;is this correct!!!&lt;/main&gt;
    &lt;/main&gt;
    &lt;footer&gt;&lt;/footer&gt;
  </code></pre>