Re: MUST use normative language (Re: draft-ietf-httpbis-http2 feedback)

Julian Reschke <julian.reschke@gmx.de> Thu, 01 August 2013 07:14 UTC

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Date: Thu, 01 Aug 2013 09:12:11 +0200
From: Julian Reschke <julian.reschke@gmx.de>
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To: Eliot Lear <lear@cisco.com>
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Subject: Re: MUST use normative language (Re: draft-ietf-httpbis-http2 feedback)
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On 2013-07-31 19:37, Eliot Lear wrote:
> I have two problems with the above and one overarching concern that
> really needs to be addressed.  First, the above text is taken out of
> context.  Flow control windows MUST always be obeyed by the sender. It
> says so right in the previous paragraph.
>
> Second,  if you don't agree with the above, changing "MAY" to "can"
> doesn't get around the fact that you're giving advice to implementers on
> the use of flow control, and yet that advice would be wrong because it
> could be ignored by senders.  This is, in other words, a distinction
> without a difference.
>
> And this brings me to my general concern.  Stop running away from
> normative language.  This WG is writing a specification that is intended
> to be very widely deployed.  It is intended to supplant the most widely
> deployed application protocol ever, and therefore interoperability and
> deterministic behavior is important.  So is the use of standard
> well-known normative terms.  They are carefully defined with specific
> meanings that are well known that most programmers understand.  They are
> *so* well known that many standards organizations have adopted them.
>
> Lastly, these words are contained in a voluntary standard.  If you don't
> follow them, the IETF believes that you may have an interoperability,
> performance, or security problem, and in some cases you might cause
> problems for others.

The problem that I have with this "MAY" is that it states something 
obvious; we have a flow control feature, and a party in the data flow 
can invoke it. Why is there a "MAY" here?

Best regards, Julian