Re: [Idr] [Technical Errata Reported] RFC4271 (5000)

"Adrian Farrel" <adrian@olddog.co.uk> Thu, 20 April 2017 14:00 UTC

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Reply-To: <adrian@olddog.co.uk>
From: "Adrian Farrel" <adrian@olddog.co.uk>
To: "'Nick Hilliard'" <nick@foobar.org>, "'Alvaro Retana \(aretana\)'" <aretana@cisco.com>
Cc: <idr@ietf.org>
References: <20170419173711.71458B814DA@rfc-editor.org> <88AF5CD0-3DA4-4CD0-877B-39925DC7D5F0@cisco.com> <58F88C2E.50809@foobar.org>
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Date: Thu, 20 Apr 2017 14:59:40 +0100
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Subject: Re: [Idr] [Technical Errata Reported] RFC4271 (5000)
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Sorry, but no!

OLD
   Others are discretionary and MAY
   or MAY NOT be sent in a particular UPDATE message.
NEW
   Others are discretionary and MAY
   be sent in a particular UPDATE message.
END

The use of MAY implies the not case.

"MAY or MUST NOT" is entirely ambiguous since "MUST NOT" means
never/forbidden/death-by-vampire so saying "or MUST NOT" is like saying "You
must never, ever, eat lithium disulfide, except when you do."

Adrian


> -----Original Message-----
> From: Idr [mailto:idr-bounces@ietf.org] On Behalf Of Nick Hilliard
> Sent: 20 April 2017 11:24
> To: Alvaro Retana (aretana)
> Cc: idr@ietf.org
> Subject: Re: [Idr] [Technical Errata Reported] RFC4271 (5000)
> 
> Alvaro Retana (aretana) wrote:
> > I would like to get input from the WG as to the best way to handle this
report.  I
> would specially like to hear from implementers, but all input is welcome.
> [...]
> > b. s/MAY NOT/MUST NOT
> 
> this.
> 
> Nick
> 
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