title: How to use HTML5 features with XHTML
body: <p>I need some help with web programming. I have to do this assignment from school and the prof has given details on the structuring. One of them is that my site should be XHTML compliant (Strict or Transitional). Another is that I need to use at least one HTML5 feature. How do I use an HTML5 feature if none of the new tags will validate with XHTML?</p>
  
  <p>I am declaring it as XHTML 1.0 Transitional. </p>
  
  <p>Here is my HTML code where I am having trouble.</p>
  
  <pre><code>&lt;body id="index" class="home"&gt;
  &lt;header id="banner" class="body"&gt;
  &lt;h1&gt;&lt;a href="#"&gt;Header1 &lt;/a&gt;&lt;/h1&gt;
  
  &lt;nav&gt;&lt;ul&gt;
  &lt;li class="active"&gt;&lt;a href="#"&gt;home&lt;/a&gt;&lt;/li&gt;
  &lt;li&gt;&lt;a href="#"&gt;portfolio&lt;/a&gt;&lt;/li&gt;
  &lt;li&gt;&lt;a href="#"&gt;blog&lt;/a&gt;&lt;/li&gt;
  &lt;li&gt;&lt;a href="#"&gt;contact&lt;/a&gt;&lt;/li&gt;
  &lt;/ul&gt;&lt;/nav&gt;
  
  &lt;/header&gt;
  &lt;/body&gt;
  </code></pre>
  
  <p>In the line with header and nav, it says the elements are undefined and that there are no attributes id and class in header. Please help.</p>
  
  <p>Thanks.</p>