title: 404 Not Found or Bad Request?
body: <p>Let's say that we have the following REST call:</p>
  
  <pre><code>GET api/companies/5 
  </code></pre>
  
  <p><em>(get company with id 5)</em></p>
  
  <p>If company '5' doesn't exist, we would typically return a <code>404 Not Found</code> response.</p>
  
  <p>But now, let's take this call:</p>
  
  <pre><code>GET api/companies/5/invoices/10 
  </code></pre>
  
  <p><em>(get invoice 10 from company 5)</em></p>
  
  <p>Now, if company '5' doesn't exist, do we still return a <code>404 Not Found</code>?  Or should a 404 only be returned if the outer most resource can not be found (invoice 10, in this case).  </p>
  
  <p>Would <code>Bad Request</code> perhaps be a better option?</p>