title: What key is used for raw HTTP POST body?
body: <p>I am testing an APIs that require raw POST body request parameter(the JSON request body in the raw format and with type <code>application/json</code>). I am testing the APIs in POSTMAN(classified areas blacked out):</p>
  
  <p><a href="https://i.stack.imgur.com/5yfr9.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5yfr9.png" alt="enter image description here"></a></p>
  
  <p>As far my experience has been, there is always a <em>Key</em> that pairs a value(like <em>Key-Value</em> pair) in the POST body.(otherwise, how will you parse and fetch any attached data in the body ever?). Be it a <em>x-www-form-urlencoded request</em> or a <em>Multipart request</em>, you are required to defined some key to pair the corresponding value.</p>
  
  <p>What's surprising is that the raw request body doesn't require any key specifically. Or, I am thinking that it has some internally generated well-known default key that every other server knows.</p>
  
  <p>What is the underlying story here? What is the name of the default generated key if there is one indeed?</p>