[UA-EAI] [Ext] RE: [UA-Coordination] Revised UASG013 - Quick Guide to EAI

Mon Jan 23 20:55:30 UTC 2017

What is meant by “bi-directional” in this context? I think you mean “can handle bi-directional domain names”. ASCII characters are inherently Left-to-right and hence never bidirectional.

From: ua-eai-bounces at icann.org [mailto:ua-eai-bounces at icann.org] On Behalf Of Don Hollander
Sent: Monday, January 23, 2017 11:28 AM
To: Mark Svancarek <marksv at microsoft.com>; HEALTH Yao <yaojk at cnnic.cn>; ua-eai at icann.org
Cc: ua-coordination at icann.org
Subject: Re: [UA-EAI] [Ext] RE: [UA-Coordination] Revised UASG013 - Quick Guide to EAI

This is what I have now:

Punycode is an algorithm that converts a non-ASCII domain string into an ASCII string.  ASCII strings that have gone through the Punycode process can be identified by a prefix of xn--.   The Punycode algorithm is bi-directional.  See https://tools.ietf.org/html/rfc3492<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftools.ietf.org%2Fhtml%2Frfc3492&data=02%7C01%7Cstuartst%40exchange.microsoft.com%7C36a667bd28d74362262008d443c5ebde%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636207964727009377&sdata=WjtnPYPKNEpGDJS%2ByeUCwtiIcZrPN0A9Kfi65FJG%2FLs%3D&reserved=0>

From: Mark Svancarek <marksv at microsoft.com<mailto:marksv at microsoft.com>>
Date: Tuesday, 24 January 2017 at 8:23 AM
To: HEALTH Yao <yaojk at cnnic.cn<mailto:yaojk at cnnic.cn>>, Don Hollander <don.hollander at icann.org<mailto:don.hollander at icann.org>>, "ua-eai at icann.org<mailto:ua-eai at icann.org>" <ua-eai at icann.org<mailto:ua-eai at icann.org>>
Cc: "ua-coordination at icann.org<mailto:ua-coordination at icann.org>" <ua-coordination at icann.org<mailto:ua-coordination at icann.org>>
Subject: [Ext] RE: [UA-EAI] [UA-Coordination] Revised UASG013 - Quick Guide to EAI

Good catch.  The ACE prefix indicates to a parser that the following string is the Punycoded transformation of an IDNA-compatible Unicode string, but is not actually a part of that transformation.

From: ua-eai-bounces at icann.org<mailto:ua-eai-bounces at icann.org> [mailto:ua-eai-bounces at icann.org] On Behalf Of Jiankang Yao
Sent: Sunday, January 22, 2017 6:27 PM
To: Don Hollander <don.hollander at icann.org<mailto:don.hollander at icann.org>>; ua-eai at icann.org<mailto:ua-eai at icann.org>
Cc: ua-coordination at icann.org<mailto:ua-coordination at icann.org>
Subject: Re: [UA-EAI] [UA-Coordination] Revised UASG013 - Quick Guide to EAI

Hello,

  The definition
"Punycode is an algorithm that converts an IDN into an ASCII string that starts with xn--. The Punycode
algorithm is bi-directional. " needs some adjustment.

xn--abcdeddaa
where  "xn--" is a prefix and "abcdeddaa" is  output of the Punycode algorithm. So Punycode output does not include "xn--".

======================================following are texts from RFC5890===============================
" the string following "xn--" must be the valid output of the Punycode algorithm
                    and must be convertible into valid U-label form."

"An "A-label" is the ASCII-Compatible Encoding (ACE, see
      Section 2.3.2.5[tools.ietf.org]<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__tools.ietf.org_html_rfc5890-23section-2D2.3.2.5%26d%3DDwMGaQ%26c%3DFmY1u3PJp6wrcrwll3mSVzgfkbPSS6sJms7xcl4I5cM%26r%3DYI0XKyKCabKQi3GVWLvuoyCWjH9WBgEBxLbMnmhSRwo%26m%3DBlmXaoCPWCepJaObWnF2dxt9iWGbbiOpvcLFcE72yiQ%26s%3DpVYrcRj8qDnXLusjJSD5ci_0RHGnYkWft7975YQvnNY%26e%3D&data=02%7C01%7Cstuartst%40exchange.microsoft.com%7C36a667bd28d74362262008d443c5ebde%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636207964727019385&sdata=umL2X7%2F2HD1OCgELj%2BoDG%2FCLtYU%2FuTlCLRWGkFZ6Hxg%3D&reserved=0>) form of an IDNA-valid string.  It must be a
      complete label: IDNA is defined for labels, not for parts of them
      and not for complete domain names.  This means, by definition,
      that every A-label will begin with the IDNA ACE prefix, "xn--"
      (see Section 2.3.2.5[tools.ietf.org]<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__tools.ietf.org_html_rfc5890-23section-2D2.3.2.5%26d%3DDwMGaQ%26c%3DFmY1u3PJp6wrcrwll3mSVzgfkbPSS6sJms7xcl4I5cM%26r%3DYI0XKyKCabKQi3GVWLvuoyCWjH9WBgEBxLbMnmhSRwo%26m%3DBlmXaoCPWCepJaObWnF2dxt9iWGbbiOpvcLFcE72yiQ%26s%3DpVYrcRj8qDnXLusjJSD5ci_0RHGnYkWft7975YQvnNY%26e%3D&data=02%7C01%7Cstuartst%40exchange.microsoft.com%7C36a667bd28d74362262008d443c5ebde%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636207964727019385&sdata=umL2X7%2F2HD1OCgELj%2BoDG%2FCLtYU%2FuTlCLRWGkFZ6Hxg%3D&reserved=0>), followed by a string that is a valid output
      of the Punycode algorithm [RFC3492[tools.ietf.org]<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-3A__tools.ietf.org_html_rfc3492%26d%3DDwMGaQ%26c%3DFmY1u3PJp6wrcrwll3mSVzgfkbPSS6sJms7xcl4I5cM%26r%3DYI0XKyKCabKQi3GVWLvuoyCWjH9WBgEBxLbMnmhSRwo%26m%3DBlmXaoCPWCepJaObWnF2dxt9iWGbbiOpvcLFcE72yiQ%26s%3DjCRt2-_j5ej-m1d0rLwe33qWNVkKM_A9b7YM6k1oYn8%26e%3D&data=02%7C01%7Cstuartst%40exchange.microsoft.com%7C36a667bd28d74362262008d443c5ebde%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636207964727019385&sdata=1Vf1%2BKna1z5v0CB2z%2FvA6oVjzBI8l5FzOy%2BY0MPEJOM%3D&reserved=0>] and hence a maximum of 59
      ASCII characters in length. "

________________________________
Jiankang Yao

From: Don Hollander<mailto:don.hollander at icann.org>
Date: 2017-01-22 17:33
To: ua-eai at icann.org<mailto:ua-eai at icann.org>
CC: Tan Tanaka, Dennis<mailto:dtantanaka at verisign.com>; Mark Svancarek via UA-Coordination<mailto:ua-coordination at icann.org>; Dr. AJAY D A T A<mailto:ajay at data.in>; Stuart Stuple<mailto:stuartst at exchange.microsoft.com>
Subject: [UA-Coordination] Revised UASG013 - Quick Guide to EAI
Last month I sent out a formatted Quick Guide to EAI.

This resulted in a number of comments from Ajay, Stuart, Mark, Lars & Dennis.

These enhancements were mostly focused on the Email Service Provider.

I have revised the source document which is attached.

And for reference, I’m also including the formatted earlier draft.

Could I please get any final comments by the end of this week (25th)?

Thanks.

Don

Don Hollander
Universal Acceptance Steering Group
Skype: don_hollander

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