title: Sending data with CURL GET
body: <p>I thought GET is not supposed to have a body. But in the context of elasticsearch, I keep seeing this kind of query (<a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/search-multi-search.html" rel="nofollow">see here for instance</a>):</p>
  
  <pre><code>curl -XGET localhost:9200/test/_msearch --data-binary @requests; echo
  </code></pre>
  
  <p>How is the binary data sent in this case? Can somebody explains what is going on and how this works?
  I first thought it was converted to a POST but, I put a proxy in front of  Elasticsearch and saw that curl was really sending a GET. Though I could find the data neither in the header, nor in the parameter, nor in the body. So it seems like my proxy also got confused by this request.</p>
  
  <p>But when I execute the request directly against elasticsearch, it works just fine. What gives?</p>