#532 draft-ietf-httpbis-p1-messaging-25, "5.7.2 Transformations"

<http://greenbytes.de/tech/webdav/draft-ietf-httpbis-p1-messaging-25.html#rfc.section.5.7.2>:

"A non-transforming proxy MUST NOT modify the message payload (Section 
3.3 of [Part2]). A transforming proxy MUST NOT modify the payload of a 
message that contains the no-transform cache-control directive.

A transforming proxy MAY transform the payload of a message that does 
not contain the no-transform cache-control directive; if the payload is 
transformed, the transforming proxy MUST add a Warning header field with 
the warn-code of 214 ("Transformation Applied") if one does not already 
appear in the message (see Section 5.5 of [Part6]). If the payload of a 
200 (OK) response is transformed, the transforming proxy can also inform 
downstream recipients that a transformation has been applied by changing 
the response status code to 203 (Non-Authoritative Information) (Section 
6.3.4 of [Part2])."

In the IESG review comments, Pete Resnick notes:

> I get the second sentence. But isn't the first a definition of a non-transforming proxy? Is so, I think you should change "MUST NOT" to "will not" or "does not".

I really don't care whether we phrase this as a statement of fact or a 
requirement.

What bothers me more is that we have two normative requirements on 
transforming proxies, split over two paragraphs.

Maybe we should re-structure this, as in...:

"A non-transforming proxy MUST NOT modify the message payload (Section 
3.3 of [Part2]).

A transforming proxy MUST NOT modify the payload of a message unless it 
does not contain the no-transform cache-control directive; if the 
payload is transformed, the transforming proxy MUST add a Warning header 
field with the warn-code of 214 ("Transformation Applied") if one does 
not already appear in the message (see Section 5.5 of [Part6]). If the 
payload of a 200 (OK) response is transformed, the transforming proxy 
can also inform downstream recipients that a transformation has been 
applied by changing the response status code to 203 (Non-Authoritative 
Information) (Section 6.3.4 of [Part2])."

?

Best regards, Julian

Received on Thursday, 16 January 2014 22:34:47 UTC