title: Where the API Token should be put in standard form? Header or URI?
body: <p>I'm developing an API using ASP.Net WebAPI, and authorizing clients with an access token. I want to know which source is more standard to put the access token? Headers, Uri or Body?
  For example in Instagram API, clients should pass access token in uri as a query string. But I think in Twitter API the request must include an Authorization header. </p>
  
  <p>Let me know if there is an standard rule.</p>