title: Do I need to name the url when using app.add_url_rule?
body: <p>From the Flask docs:</p>
  
  <pre><code>def index():
      pass
  app.add_url_rule('/', 'index', index)
  </code></pre>
  
  <p>It also says:</p>
  
  <blockquote>
    <p>endpoint – the endpoint for the registered URL rule. Flask itself assumes the name of the view function as endpoint</p>
  </blockquote>
  
  <p>Indeed, if I do <code>app.add_url_rule('/', None, index)</code> it all seems to work fine. (I'm not sure of the terminology and what an "endpoint" actually is.)</p>
  
  <p>Some further questions:</p>
  
  <ol>
  <li><p>Is there any reason to specify the second argument?</p></li>
  <li><p>Is the second argument indeed the "endpoint"?</p></li>
  <li><p>What are the benefits/drawbacks of (not) specifying the second argument?</p></li>
  <li><p>What if the same name is used in another url rule? Is the first overwritten? Is this intended?</p></li>
  </ol>