Re: [precis] names and usernames

Peter Saint-Andre <> Sun, 26 February 2017 23:32 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 4DC6C1295C8 for <>; Sun, 26 Feb 2017 15:32:33 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2.701
X-Spam-Status: No, score=-2.701 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (1024-bit key) header.b=fIxLdmK0; dkim=pass (1024-bit key) header.b=KBtil2Vq
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id zrx7QWSPiV1n for <>; Sun, 26 Feb 2017 15:32:32 -0800 (PST)
Received: from ( []) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 0A70A129516 for <>; Sun, 26 Feb 2017 15:32:31 -0800 (PST)
Received: from compute2.internal (compute2.nyi.internal []) by mailnew.nyi.internal (Postfix) with ESMTP id 5B7389D4B; Sun, 26 Feb 2017 18:32:30 -0500 (EST)
Received: from frontend1 ([]) by compute2.internal (MEProxy); Sun, 26 Feb 2017 18:32:30 -0500
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed;; h= content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc:x-sasl-enc; s=mesmtp; bh=TORnEcKil5k8fq8 DywRdphr/IwE=; b=fIxLdmK0D82ccLgfSXDeYxnxYrlkzE2hK/UxOfjM2PXzavt QkNqqxBvcNB1gcmE8LXA9BBcek0yhrC6b+Brrc8aBMw+PXdzDLgi0naDfF+X4acS /SEIpk4SaTctYHLa0tIATv2p08ct3s7JXbt2/t9qiEC55VE8LpJQjVwO3ud8=
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=; h=content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc:x-sasl-enc; s= smtpout; bh=TORnEcKil5k8fq8DywRdphr/IwE=; b=KBtil2VqzcM1yWLsAPjM 74wgO3run4a/Ur69qdH8C833TLTEcBGZW7jPRx28i8XytzFOYIAfU2f5Ld/I3Ebw YqQtPe88TXx8a1NWtcwbgO9eqkbgnkpZfgVduQ/70BcfM6psDg/YvwlvxPeRqjaT +M9Fvqu4W4nzZ0OaAcWIV08=
X-ME-Sender: <xms:jmWzWBLik2EJmV0xRwlPX7Ef8LxkLYDPjLjAbH8fxYhU1k0Ouf94Jw>
X-Sasl-enc: MqZyr9lNBcJLFeFRIPT80Eq0/T2gPIJM7ypOcZdUgEnO 1488151949
Received: from aither.local (unknown []) by (Postfix) with ESMTPA id 92FBE7E070; Sun, 26 Feb 2017 18:32:29 -0500 (EST)
To: Florian Zeitz <>,
References: <> <>
From: Peter Saint-Andre <>
Message-ID: <>
Date: Sun, 26 Feb 2017 16:32:28 -0700
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:45.0) Gecko/20100101 Thunderbird/45.7.1
MIME-Version: 1.0
In-Reply-To: <>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Archived-At: <>
Subject: Re: [precis] names and usernames
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: Preparation and Comparison of Internationalized Strings <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Sun, 26 Feb 2017 23:32:33 -0000

On 2/12/17 8:15 PM, Florian Zeitz wrote:
> Am 13.02.2017 um 00:29 schrieb Peter Saint-Andre:
>> John Klensin has brought to my attention that it is currently impossible
>> to represent some people's names in PRECIS usernames because some of the
>> relevant Unicode code points are disallowed by the IdentifierClass
>> defined in RFC 7564 (and thus by the UsernameCaseMapped and
>> UsernameCasePreserved profiles defined in RFC 7613).
>> First, RFC 7564 disallows "default ignorable" code points in the
>> IdentifierClass. However, as I understand it some of these code points
>> are need to represent characters in names that might be desirable to
>> people living within communities that use Indic script and eastern
>> Arabic script (e.g., Persian and writing systems derived from Persian).
>> In particular, the Unicode Standard specifies that ZWJ and ZWNJ are
>> "default ignorable" and it seems that these code points are especially
>> important in this context.
> I'd have to look at it in more detail, but that assessment seems wrong
> to me.
> Algorithmically we check for JoinControl before
> PrecisIgnorableProperties, making ZWJ and ZWNJ CONTEXTJ.
> That allows them to occur after virama and where they break a cursive
> connections. 


> I'm not sure those are the only cases that John is
> concerned about, but they are not generally disallowed as I understand it.

Because I don't have a good understanding of the relevant scripts and
languages, I am dependent on people who do, such as Nalini Elkins. I
shall ping her again to see if she can share her insights.

> That said, I always found it a bit unsettling that it is virtually
> impossible to determine the algorithmic result from the textual
> description of what is and isn't allowed.

There is much that is unsettling about internationalization. We do the
best we can with what is given.