Re: p6: Returning the freshest response

Martin Thomson <martin.thomson@gmail.com> Fri, 29 March 2013 22:33 UTC

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Date: Fri, 29 Mar 2013 15:32:14 -0700
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From: Martin Thomson <martin.thomson@gmail.com>
To: Mark Nottingham <mnot@mnot.net>
Cc: Ken Murchison <murch@andrew.cmu.edu>, HTTP Working Group <ietf-http-wg@w3.org>, Roy Fielding <fielding@gbiv.com>, "Julian F. Reschke" <julian.reschke@gmx.de>
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Subject: Re: p6: Returning the freshest response
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On 29 March 2013 15:11, Mark Nottingham <mnot@mnot.net> wrote:
>> The SHOULD is qualified sufficiently that I believe that a MUST is
>> more appropriate.
>
> The requirement is of the form "SHOULD... unless...", with the clause:
>
>> , unless the variance cannot be crossed or the origin server has been deliberately configured to prevent cache transparency.
>
> so I think this one is OK.

I'm not familiar with the "SHOULD...unless" construct.
"MUST...unless" is better typically, unless there are other,
unspecified reasons that this directive can be ignored.