+// It is possible to serve untrusted content and accept user
+// credentials at the same origin as long as the content is only
+// downloaded, never executed by browsers. A single origin (hostname
+// and port) can be designated as an "attachment-only" origin: cookies
+// will be accepted and all responses will have a
+// "Content-Disposition: attachment" header. This behavior is invoked
+// only when the designated origin matches exactly the Host header
+// provided by the client or downstream proxy.