title: Can headers always be combined?
body: <p>If I have two headers with the same name (and assuming that this makes sense and is valid)</p>
  
  <pre><code>Some-Header: foo
  Some-Header: bar
  </code></pre>
  
  <p>can they always be combined?</p>
  
  <pre><code>Some-Header: foo,bar
  </code></pre>
  
  <p>I am looking for guarantees (or lack thereof) made by the HTTP RFCs. (If the standards differ from practice, I'd be interested in hearing that too.)</p>