title: What is the "Default callback URL:" for Tumblr API v2?
body: <p>Hi I am trying to use Tumblr API v2 and OAuth
  <a href="http://www.tumblr.com/docs/en/api/v2" rel="noreferrer">http://www.tumblr.com/docs/en/api/v2</a></p>
  
  <p>First I have to register an application here: <a href="http://www.tumblr.com/oauth/apps" rel="noreferrer">http://www.tumblr.com/oauth/apps</a></p>
  
  <p>But what is the "Default callback URL"? Some random URL?</p>
  
  <p>I just want to write to a Python program to make some posts using command line.</p>
  
  <p>Thanks a lot!</p>