Re: Last Call: <draft-leiba-cotton-iana-5226bis-12.txt> (Guidelines for Writing an IANA Considerations Section in RFCs) to Best Current Practice

Brian E Carpenter <brian.e.carpenter@gmail.com> Tue, 26 April 2016 23:47 UTC

Return-Path: <brian.e.carpenter@gmail.com>
X-Original-To: ietf@ietfa.amsl.com
Delivered-To: ietf@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 537DD12D1AE; Tue, 26 Apr 2016 16:47:14 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.7
X-Spam-Level:
X-Spam-Status: No, score=-2.7 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id nKw79ufzHNAV; Tue, 26 Apr 2016 16:47:13 -0700 (PDT)
Received: from mail-pf0-x22f.google.com (mail-pf0-x22f.google.com [IPv6:2607:f8b0:400e:c00::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 0958B12D10D; Tue, 26 Apr 2016 16:47:13 -0700 (PDT)
Received: by mail-pf0-x22f.google.com with SMTP id y69so12906392pfb.1; Tue, 26 Apr 2016 16:47:13 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:cc:from:organization:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=pKSwkUvG060MFRYWcvwSHpo+enBIr5nXY6ATGj/w+6k=; b=e4sLS0zobt4xCxaCqZSLM4niZF9JflZaFRY0Lj/edo5UigOPsuzZ8hnrWdv7MMv7sI YTpiIRoAV49A7WWZTRYfFTAWx3d9ERllBrUbB/sqAZJfXWkW5gRaIoq6VMydAYIrgmBZ gsY+gBTKf1fVvA64kDZ65cvQqKVknnT0LUYkOXFy2+6kiDvFeVWbLXBtpNE7gMlDzexI y7zuCZCTMjnn1Pxhq60EbRHpJOIGcGabEiDlZbwxCyQ+yJrRoh3FZm/nPIvEbbbVXAf2 YLpSm0MsOZ2mx5uLfxeLC7juNbAIMk28b82yjKRyMc5tk7TjomCI+YgK3/7w698q8xpT cOow==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:cc:from:organization :message-id:date:user-agent:mime-version:in-reply-to :content-transfer-encoding; bh=pKSwkUvG060MFRYWcvwSHpo+enBIr5nXY6ATGj/w+6k=; b=RKVaJ84tE2iBGbsk6H4bi2U7d1j2QCv2Jfap269PF91oLtDmdZRKlWX+LS/4Hmv/Mx TFp4ipy+LEN82qvVE/JfEACvkjKfN9Zy34JI/hGjLpqvcf1gm8lmI9SagOQCK5pv9rRv x5B4OeEJGrKK78NgbvkKaVNN+yySuIfLrMWDliUYPKN/ZVAepRus7iyIfDHtzvkciFxW garHGU5GMCVWmJ1bmzbRk8lcd/GsTtRbpkJ+4uYfZs25UpGVLoUs8FAYY5t1nXaVITgU 3Ly7osLtH4SIRWtisVc5AijB+TIiqAW4YqAc3V6EROCzG/S892YAmsd13K9OT6RXD4u8 fXUg==
X-Gm-Message-State: AOPr4FVnFuF91pcVNiG20BSAjPqV3t8zqHYcc8VTwFOCi7FkTvcNZRKGDqY9gXtm6zE9fw==
X-Received: by 10.98.32.211 with SMTP id m80mr7532107pfj.3.1461714432610; Tue, 26 Apr 2016 16:47:12 -0700 (PDT)
Received: from ?IPv6:2406:e007:79e1:1:28cc:dc4c:9703:6781? ([2406:e007:79e1:1:28cc:dc4c:9703:6781]) by smtp.gmail.com with ESMTPSA id q72sm998441pfa.70.2016.04.26.16.47.09 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 26 Apr 2016 16:47:11 -0700 (PDT)
Subject: Re: Last Call: <draft-leiba-cotton-iana-5226bis-12.txt> (Guidelines for Writing an IANA Considerations Section in RFCs) to Best Current Practice
To: adrian@olddog.co.uk, ietf@ietf.org
References: <20160419141640.31545.54742.idtracker@ietfa.amsl.com> <057701d19ffa$2291b5b0$67b52110$@olddog.co.uk>
From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Organization: University of Auckland
Message-ID: <44038e4c-d177-3f06-7f40-dd82cbd86a99@gmail.com>
Date: Wed, 27 Apr 2016 11:47:14 +1200
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.0
MIME-Version: 1.0
In-Reply-To: <057701d19ffa$2291b5b0$67b52110$@olddog.co.uk>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Archived-At: <http://mailarchive.ietf.org/arch/msg/ietf/uYuA7DzmwdeOYxrRNvpm-_w2yKA>
Cc: draft-leiba-cotton-iana-5226bis@ietf.org
X-BeenThere: ietf@ietf.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: IETF-Discussion <ietf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ietf>, <mailto:ietf-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ietf/>
List-Post: <mailto:ietf@ietf.org>
List-Help: <mailto:ietf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ietf>, <mailto:ietf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 26 Apr 2016 23:47:14 -0000

On 27/04/2016 08:28, Adrian Farrel wrote:
...
> Section 6
> Include hint on best practice for top and bottom of ranges.
> OLD
>      Reserved: Not assigned and not available for assignment.  Reserved
>            values are held for special uses, such as to extend the
>            namespace when it becomes exhausted.  Note that this is
>            distinctly different from "Unassigned".
> NEW
>      Reserved: Not assigned and not available for assignment.  Reserved
>            values are held for special uses, such as to extend the
>            namespace when it becomes exhausted.  Note that this is
>            distinctly different from "Unassigned".
> 
>           It is common practice for documents that define numeric registries
>           to mark the zero value as "Reserved" because this often aids protocol 
>           implementations.

I'm not sure about the "because" clause. It sounds a bit like an excuse for
sloppy coding. Defining it explicitly as a no-op would seem like better
practice in many cases.

   Brian

>           It is also common practice to mark the maximum
>           value as "Reserved" so that it can be used as part of a strategy to
>           extend the registry if the range proves too small in the future.
> END
> 
> Thanks,
> Adrian
> 
>