title: Sitecore Field Renderer - add markup inside rendering
body: <p>As part of an SEO enhancement project, I've been tasked with adding the following property inside the markup for the image that the field renderer is generating on the page:</p>
  
  <p><code>itemprop="contentURL"</code> - before the closing tag. </p>
  
  <pre><code>&lt;sc:FieldRenderer ID='FieldRenderer_MainImage' Runat='server' FieldName='Homepage Image'
      CssClass="_image" Parameters="w=150" itemprop="contentURL" /&gt;
  </code></pre>
  
  <p>When I tried to place this inside the Field Renderer, or add it as a "parameter" - it doesn't work.</p>
  
  <p>Is there another way to do this, without having to create a control file and generate the output in the code-behind?</p>