title: HTML - Undeletable placeholder in input element
body: <p>I have an URL field in my form.
  The validator requires for it to have <code>http://</code> in front of it, 
  which I think many people won't understand.</p>
  
  <p>Could I have a "placeholder" that the user cannot delete or write before it?</p>
  
  <p>Example: <strong>http://</strong> myinputhere.com</p>
  
  <p><code>&lt;input type="url" placeholder="http://"&gt;</code> </p>