Question about proxies forwarding HTTP/1.0 responses

In RFC 2616 it says:

   Proxy and gateway applications need to be careful when forwarding
   messages in protocol versions different from that of the application.
   Since the protocol version indicates the protocol capability of the
   sender, a proxy/gateway MUST NOT send a message with a version
   indicator which is greater than its actual version. If a higher
                                   ^^^^^^^^^^^^^^^^^^
   version request is received, the proxy/gateway MUST either downgrade
   the request version, or respond with an error, or switch to tunnel
   behavior.

I'm having trouble parsing the highlighted sentence part.  Does "its
actual version" refer to the version of the message, or the version of
the proxy/gateway?  I think the intention is the version of the
proxy/gateway, but the text's use of "its" is linguistically
ambiguous.

This has come up while deciding whether a proxy which is
HTTP/1.1-capable, which receives a HTTP/1.0 response, should indicate
a HTTP/1.0 version in its response to the client.

To be more precise, I'm fairly sure the proxy should indicate it is
HTTP/1.1 capable, because that's the capability of the message sender,
which is the proxy.  (It's not a tunnel).  My question really is about
the observed behaviour of widely deployed proxies over the past few
years.  Does anyone know what the behaviour of deployed proxies is?

-- Jamie

Received on Wednesday, 26 May 2004 22:25:59 UTC