title: What’s the purpose of the value request_method in Rails cookies?
body: <p>I’m wondering what’s the purpose of the value <code>request_method</code> that is found in every cookie of a Rails 4 application.</p>
  
  <pre><code>$ curl -i localhost:3000
  HTTP/1.1 200 OK 
  X-Frame-Options: SAMEORIGIN
  X-Xss-Protection: 1; mode=block
  X-Content-Type-Options: nosniff
  X-Ua-Compatible: chrome=1
  Content-Type: text/html; charset=utf-8
  Etag: "396b1283ee1adc85adf3c604a553ad74"
  Cache-Control: max-age=0, private, must-revalidate
  X-Request-Id: d8577072-a823-418c-b521-6c34dbe71645
  X-Runtime: 0.068436
  Server: WEBrick/1.3.1 (Ruby/2.0.0/2013-06-27)
  Date: Wed, 04 Dec 2013 21:16:38 GMT
  Content-Length: 4375
  Connection: Keep-Alive
  Set-Cookie: request_method=GET; path=/
  ...
  </code></pre>
  
  <p>I’ve googled for it and found no answer anywhere. Why not just use the session value?</p>