title: Header parameters: "Accept" and "Content-type" in a REST context
body: <p>I understand that the <code>Accept</code> parameter define a data type expected in a client response sent from the server, so it's used as a response header.</p>
  
  <p>My question is regarding the <code>Content-type</code>, it's used by a client to define the body format of a request sent, I always used it as part of a client request, so I have a client request where I set the headers with <code>Accept</code> and <code>Content-type</code>. And recently, I came across a project where the <code>Content-type</code> is defined in the response headers (so sent by the server). So my question is: <code>Content-type</code> need to be set as part of the client request header or as part of the server response header or can it be set to both ?</p>