Re: URN Namespace for MEF

Mahesh Jethanandani <> Mon, 09 November 2015 05:18 UTC

Return-Path: <>
Received: from localhost ( []) by (Postfix) with ESMTP id E7BDD1B6478 for <>; Sun, 8 Nov 2015 21:18:59 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.999
X-Spam-Status: No, score=-1.999 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, HTML_MESSAGE=0.001, SPF_PASS=-0.001] autolearn=ham
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id Y6qCtC1hVOuy for <>; Sun, 8 Nov 2015 21:18:58 -0800 (PST)
Received: from ( [IPv6:2607:f8b0:400e:c03::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id D364E1B6476 for <>; Sun, 8 Nov 2015 21:18:57 -0800 (PST)
Received: by padhx2 with SMTP id hx2so178537404pad.1 for <>; Sun, 08 Nov 2015 21:18:57 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20120113; h=content-type:mime-version:subject:from:in-reply-to:date:cc :message-id:references:to; bh=IN9fg/QeKFymt8OTMRF2Ef6tMw654UuWXzgndlyG16I=; b=gmVuDMxMiIBwP6Fv8IlqHdRYgOkPUreKo31rhttyzRmkRTIhVpfqXjimxuDSlsc7fV hb6BripF2BjClEJBv+eZ7SRlzsW2AOg2wcQCQLT1KAVYJeecziyDbrNFDLJY+yzZXiZn pYeSzMRFT9Yty4ngj3w4qI3nMqSkg9V8EGeZc/gZ1ApgAybu8IvmsdC1940DfMbL70Bo Q+ziUVGRix+pBLrVENixhLfAPY2EfL8ux/XOfW6YZa8i/PSsb16Jp7tA9Vjs2ZSsyo75 FvoLiGh0EsYuet9ih/MTpmNsMqV3wlmIEm1C3s6g3qyeufRnbHKommJOYn/liwxC/ysU OPcQ==
X-Received: by with SMTP id zx11mr37012704pab.125.1447046337378; Sun, 08 Nov 2015 21:18:57 -0800 (PST)
Received: from [] ([]) by with ESMTPSA id db8sm13604260pad.43.2015. (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sun, 08 Nov 2015 21:18:56 -0800 (PST)
Content-Type: multipart/alternative; boundary="Apple-Mail=_54DED31D-B639-4ED0-BF9D-069A4519AC46"
Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2098\))
Subject: Re: URN Namespace for MEF
From: Mahesh Jethanandani <>
In-Reply-To: <>
Date: Sun, 8 Nov 2015 21:18:54 -0800
Message-Id: <>
References: <>
To: "Dale R. Worley" <>
X-Mailer: Apple Mail (2.2098)
Archived-At: <>
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: discussion of new namespace identifiers for URNs <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Mon, 09 Nov 2015 05:19:00 -0000


First of all, thanks for a detailed review of the draft. 

Comments/questions inline.

> On Nov 6, 2015, at 2:57 PM, Dale R. Worley <> wrote:
> Section 2:
>   Declaration of syntactic structure:
>      The Namespace Specific String (NSS) of all URNs that use the MEF
>      NID will be maintained by MEF Assigned Names and Numbers (MANN)
>      registry.
> This doesn't specify the syntactic structure.  I assume that the
> intention is that this registration is to allow MANN to assign any NSS
> that would be allowed by the generic URN specification.

That is correct.

>  But you should
> say that.  I think you could say
>      The syntax of namespace specific strings for the 'mef' namespace
>      is <NSS> in RFC 2141.


> The statement you now have in the section describes who manages mef
> URNs, which is a useful thing, but doesn't belong in this section, I
> think.  But I can't spot the place in the registration template where it
> should go.

>   Identifier uniqueness considerations:
>      MEF could allow for use of experimental type values for testing
>      purposes only.  Note that using experimental types may create
>      collision as multiple users may use the same values for resources
>      and specific strings.
> First, you should say "for *different* resources ...".  If multiple
> users use the same value for the same resources, there is nothing
> unusual about that.
> This provision doesn't bother me, but is likely to be objected to by
> others.  And there can be practical problems -- experimental uses of
> protocols by one user sometimes "leak" into experimental environments
> operated by another use, causing unexpected results.  You should give
> some though to avoiding this, IMO.  Perhaps:
> 1) Devise a system for allocating experimental values that allows each
> user to generate values that will not be allocated by other users.
> E.g., the pattern ""; or

That is the idea. The current thought is that all experimental values will have a pattern of “urn:mef:xid:…” where xid refers to experimental id.

> 2) Define the "value" of an experimental URN in terms of its *function*
> or high-level *meaning* ("denotes the string to be returned when
> conditions X and Y occur"), allowing different users to have it be
> translated in different manners or cause different effects, but always
> with the same higher-level significance.


Mahesh Jethanandani