title: REST API standard status codes
body: <p>I Created a Rest Api for an ios app with a slim framework.
  For identifing Post requests I created my own set of status codes.
  As seen below for error responses.</p>
  
  <pre><code>{"status":"Incorrect Pin","code":3}
  {"status":"server error","code":4} 
  </code></pre>
  
  <p>But our app developer said that that does not match international standards.
  He suggested something like the following.</p>
  
  <pre><code>{"status":"Incorrect Pin","code":404}
   {"status":"servererror","code":404}
  </code></pre>
  
  <p>I know  200,404, are basic http status code but what are the international standards for such a code?
  Can anyone explain this to me?</p>