title: Are the xsi and schema portions needed in an XML sitemap? What do they mean?
body: <p>For the XML sitemap of my website, I noticed that different articles suggest different things.</p>
  
  <p>For example, prior to my page listings, some articles suggest starting it this way:</p>
  
  <pre class="lang-xml prettyprint-override"><code>  &lt;urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
     xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9 
                         http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd"&gt;
  </code></pre>
  
  <p>While other articles have it layed out using only:</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"&gt;
  </code></pre>
  
  <p>Do I need to include all of the extra stuff from the first example?</p>
  
  <p>And what exactly is the difference between using the extra parts, or not using them?</p>