title: What are the defaults, if any, for HTTP POST request headers when uploading a file?
body: <p>What I mean is for example when you send a form that includes a file upload via POST, the POST request contains certain information like "Content-Disposition", "Content-Type", "Content-Transfer-Encoding", etc.</p>
  
  <p>In the case of a file upload should "Content-Disposition" be "form-data" and "Content-Type" "application/octet-stream"? What about "Content-Transfer-Encoding"?</p>
  
  <p>More specifically, what are the defaults when you use a web form to upload a file? I ask this because I'm trying to create a POST request identical to the ones a browser sends when uploading a file. Obviously when you submit a web form you don't really specify what these request headers are; the browser must automatically set them and I'm wondering what the defaults are so I can mimic them.</p>