title: Fetch API; why use the "no-cors" mode if the response is Opaque?
body: <p>I read <a href="https://stackoverflow.com/questions/35910790/whats-the-difference-between-same-origin-and-no-cors-for-javascripts-fetch">this question</a> and  <a href="https://stackoverflow.com/a/43268098/1175496">this question</a> . The former only explains 'no-cors' vs 'same-origin'; the latter recommends that 'no-cors' is not useful because of the Opaque Response (which Javascript cannot read/do anything useful with):</p>
  
  <blockquote>
    <p>You basically never ever want to use mode: 'no-cors' in practice —
    except in some very limited cases. That’s because what setting mode:
    'no-cors' actually says to the browser is, “Block my frontend
    JavaScript code from looking into the contents of the response body
    and headers under all circumstances.” In most cases that’s obviously
    really not what you want.</p>
  </blockquote>
  
  <p>Can someone advise <strong>what are examples of these "limited cases" where we would want to use "no-cors" (even though the response is Opaque?)</strong></p>
  
  <p>The only case I can think of is a sort of one-way communication; if it is sufficient for the client to send a GET or POST to the server, <em>simply so the server can track that the request happened</em>; (for example, to increment a request counter); ...</p>
  
  <p>...then it is sufficient for the response to be an OpaqueResponse; i.e. the client only need to know if the request was successful (status 200), doesn't expect any payload response.</p>
  
  <p>Is my idea a valid example? Can someone recommend other possibilities / use-cases / examples of 'no-cors' usage?</p>