anchor.diff:  1. List your app instances and retrieve the index number of the instance you want to debug:
   	<pre class="terminal">$ cf app YOUR-APP</pre>
   
  -1. Make a request to the app route using the HTTP header `X-CF-APP-INSTANCE` set to the concatenated values of the app GUID and the instance index:
  -	<pre class="terminal">$ curl app.example.com -H "X-CF-APP-INSTANCE":"YOUR-APP-GUID:YOUR-INSTANCE-INDEX"</pre>
  -<p class="note">Use of the `X-CF-APP-INSTANCE` header is only available for users on the Diego architecture.</p>
  -If this header is set to an invalid value, Gorouter resturns a `400` status code and the response from Gorouter contains a `X-Cf-Routererror` header with more information about the error. The following table describes the possible error responses:
  +1. Make a request to the app route using the HTTP header `X-Cf-App-Instance` set to the concatenated values of the app GUID and the instance index:
  +	<pre class="terminal">$ curl app.example.com -H "X-Cf-App-Instance":"YOUR-APP-GUID:YOUR-INSTANCE-INDEX"</pre>
  +<p class="note">Use of the `X-Cf-App-Instance` header is only available for users on the Diego architecture.</p>
  +If this header is set to an invalid value, Gorouter resturns a `400` status code and the
  +response from Gorouter contains a `X-Cf-Routererror` header with more information about the error.
  +The following table describes the possible error responses:
   <table>
     <tr>
       <th width="30%">X-Cf-Routererror Value</th>
  
positive.code: 
  ### <a id="app-instance-routing"></a> HTTP Headers for App Instance Routing
  
  Developers who want to obtain debug data for a specific instance of an app can use the HTTP header `X-CF-APP-INSTANCE` to make a request to an app instance.
  
  To make an HTTP request to a specific app instance:
  
  
negative.code:   </tr> 
    <tr>
      <td><code>invalid_cf_app_instance_header</code></td>
      <td>The value provided for <code>X-Cf-App-Instance</code> was not a properly formatted GUID.</td>
      <td>None</td>
    </tr>
    <tr>
      <td><code>unknown_route</code></td>
      <td>The value provided for <code>X-Cf-App-Instance</code> is a correctly formatted GUID, but there is no instance found with that guid for the route requested.</td>
      <td><code>400 Bad Request: Requested instance ('1') with guid ('aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa') does not exist for route ('myroute.cf.com')</code></td>
    </tr>  
  </table> 
  