wdiff rfc5564.original rfc5564.txt

Network Working Group A. El-Sherbiny
Internet-Draft
Request for Comments: 5564 M. Farah
Intended status:
Category: Informational UN-ESCWA
Expires: August 9, 2009
I. Oueichek
Syrian Telecom Establishment
A. Al-Zoman
SaudiNIC, CITC
February 5,
May 2009

Linguistic Guidelines for the Use of
the Arabic Language in Internet Domains
draft-farah-adntf-ling-guidelines-04.txt

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Abstract

This document constitutes technical specifications for the use of
Arabic in Internet Domain domain names and provides linguistic guidelines
for Arabic Domain Names. domain names. It addresses Arabic-specific linguistic
issues pertaining to the use of Arabic language in domain names.

Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 ....................................................2
2. Arabic Language-Specific Issues . . . . . . . . . . . . . . . 4 .................................3
2.1. Linguistic Issues . . . . . . . . . . . . . . . . . . . . 4 ..........................................4
2.1.1. Diacritics (tashkeel) (Tashkeel) and Shadda . . . . . . . . . . . 5 ....................4
2.1.2. Kasheeda or Tatweel (Horizontal Character
Size Extension) . . . . . . . . . . . . . . . . . . . . . . 5 .....................................5
2.1.3. Character Folding . . . . . . . . . . . . . . . . . . 5 ...................................5
2.2. Supported Character Set . . . . . . . . . . . . . . . . . 6 ....................................6
2.3. Arabic Linguistic Issues Affected By Technical
Constraints . . . . . . . . . . . . . . . . . . . . . . . 8 ................................................7
2.3.1. Numerals . . . . . . . . . . . . . . . . . . . . . . . 8 ............................................7
2.3.2. The Space Character . . . . . . . . . . . . . . . . . 8 .................................8
3. Summary and Conclusion . . . . . . . . . . . . . . . . . . . . 9 ..........................................8
4. Security Considerations . . . . . . . . . . . . . . . . . . . 9 .........................................8
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9
7. .................................................9
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7.1. ......................................................9
6.1. Normative References . . . . . . . . . . . . . . . . . . . 10
7.2. .......................................9
6.2. Informative References . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11
Intellectual Property and Copyright Statements . . . . . . . . . . 12 .....................................9

1. Introduction

The Internet Engineering Task Force (IETF) issued in March 2003 a set
of RFCs for Internationalized Domain Names (IDN) [1],[2], [3] ([1], [2], and [3]),
which were planned to become the de facto standard for all languages.
In 2007 and 2008, new versions of the internet-drafts proposing the following working drafts were released that
propose revisions to the IDNA protocol have been released and are as follows: protocol:

o Internationalizing Internationalized Domain Names for Applications (IDNA): Issues
Background, Explanation, and Rationale [5]

o Internationalizing Internationalized Domain Names in Applications (IDNA): Protocol
[6]

o An updated IDNA problem in criterion for right-to-left scripts [7]

o The Unicode Codepoints code points and IDN IDNA [8]

Those

These documents are known collectively as "IDNA2008".

This document constitutes a technical specification for the
implementation of the IDN standards in the case of the Arabic
Language.
language. It will allow the use of standard language tables to write
domain names in Arabic characters. Therefore, it should be
considered as a logical extension to the IDN standards. It thus
presents guidelines for the proper use of Arabic characters with the
IDN standards in an Arabic language context.

This document reflects the recommendations of the Arab Working Group
on Arabic Domain Names (AWG-ADN) (AWG-ADN), established by the League of Arab
States (LAS), based on standardisation efforts of the United Nations
Economic and Social Commission for Western Asia (UN-ESCWA) and its
Internet- Draft, on
that group's document, "Guidelines for an Arabic Internet Domain
Name" [9].
It This document is also in full harmony with recent
rigorous discussions that took place with within the major language
communities that also use the Arabic script in their languages.

This document provides guidelines for the ways Arabic characters may
be used for registering Internet Domain Names domain names and how linguistic linguistic-
specific issues should be handled. A few rules are recommended for
application at the protocol level.

The key words "MUST", "REQUIRED", "SHOULD", "RECOMMENDED", and "MAY"
in this document are to be interpreted as described in RFC 2119 [4].

Comments on this document are solicited and should be addressed to
the working group's mailing list at ESCWA-ICTD@un.org and/or the
author(s).

2. Arabic Language-Specific Issues

The main objective of the creation of Arabic Domain Names domain names is to have
a vehicle to increase Internet use amongst all strata of the Arabic-
speaking communities.

Furthermore, a non-user friendly Domain Name non-user-friendly domain name would further add to the
ambiguity and the eccentricity of the Internet to the Arabic-speaking
communities, thus contributing negatively to the spread of the
Internet and leading to further isolation of these communities at the
global level.

Hence, there have been intensive efforts especially (especially those
spearheaded by Dr. Al-Zoman and contributed to by UN-ESCWA and its
Arabic Domain Names Task Force (ADN-TF) (ADN-TF)) to reach consensus on a
multitude of linguistic issues with the following goals:

o To define the accepted Arabic character set to be used for writing
domain names in Arabic; Arabic, which is the subject of this document.

o To define the top-level domains of the Arabic domain name tree
structure (i.e., Arabic gTLDs and ccTLDs). This goal will be
handled in a separate document.

The first meeting of the AWG-ADN, held in Damascus January-February from January-
February 2005, gave special attention to the following:

o Simplification of the domain names, whenever possible, to
facilitate the interaction of the Arabic user with the Internet.

o Adoption of solutions that do not lead to confusion either in
reading or in writing, provided that this does not compromise the
linguistic correctness of used words.

o Mixing Arabic and non-Arabic letters in the domain name label is
not acceptable.

2.1. Linguistic Issues

There are a number of linguistic issues that have been proposed with
respect to the use of the Arabic language in domain names. This
section will highlight some of them. This section is based on the
papers of Dr. Al-Zoman [10] [11] ([10] and [11]) and on the report of the first
meeting of AWG-ADN [12]. For details details, the reader is encouraged to
review the these references.

2.1.1. Diacritics (tashkeel) (Tashkeel) and Shadda

Tashkeel and Shadda are accent marks placed above or below Arabic
letters to produce proper pronunciation. They are thus used to
differentiate different meanings for different words with the same
base characters.

Neither Tashkeel nor Shadda are permitted in zone files when
registering domain names in the Arabic language, although they are
permitted in the current edition of IDNA2008. They can be supported
or ignored, if necessary, in the user interface with local mappings
and can be stripped before IDNA processing.

The following are their Unicode presentations:

U+064B ARABIC FATHATAN
U+064C ARABIC DAMMATAN
U+064D ARABIC KASRATAN
U+064E ARABIC FATHA
U+064F ARABIC DAMMA
U+0650 ARABIC KASRA
U+0651 ARABIC SHADDA
U+0652 ARABIC SUKUN

2.1.2. Kasheeda or Tatweel (Horizontal Character Size Extension)

Kasheeda (U+0640 ARABIC TATWEEL) must not be used in Arabic domain
names and should be disallowed for Arabic language domain names. The
Kasheeda is not a letter and does not have an effect on
pronunciation. It is used to extend the horizontal length or change
the shape of the preceding letter for graphical representation
purposes in Arabic writing. Accordingly, it has no value for the
writing of domain names. The same applies to all languages using the
Arabic script. The authors recommend that it should be disallowed at
the protocol level.

2.1.3. Character Folding

Character folding is the process where multiple letters (that may
have some similarity with respect to their shapes) are folded into
one shape. Examples of such Arabic characters include:

o Folding Teh Marbuta (U+0629) and Heh (U+0647) at the end of a
word; word

o Folding different forms of Hamzah (U+0622, U+0623, U+0625,
U+0627); U+0627)

o Folding Alef Maksura (U+0649) and Yeh (U+064A) at the end of a
word;
word

o Folding Waw with Hamzah Above (U+0624) and Waw (U+0648). (U+0648)

With respect to the Arabic language, character folding is not
acceptable because it changes the meaning of words and it is against the
principle of spelling rules. Replacing a character valid for use in
domain names with another character also valid for use in domain
names, which may have a similar shape, will give a different meaning.
This will lead to have only one word representing several words consisting
of all the combinations of folded characters. Hence, the other words
will be masked by a single word [10].

Mis-spelling or handwriting errors do occur occur, leading to mixing
different characters despite the fact that this is not the case in
published and printed materials. One of the motivations of this
effort is to preserve the language language, particularly with the spread of
the globalization movement. Within this context, character folding
is working against this motivation since it is going to have a
negative affect effect on the principle and ethics of the language.
Technology should work for preserving to preserve the language and not for
destroying to destroy
it. Thus, character folding should not be allowed. The case of
digits is treated in a separate section below.

2.2. Supported Character Set

A domain name to be written in Arabic must be composed of a sequence
of the following UNICODE characters and the FULL STOP (u+002E) to
seperate
separate the labels. These are based on UNICODE version 5.0. The
tables below are constructed using an inclusion-based approach.
Thus, characters that are not part of the table these tables are prohibited.

+---------+-------------------------------------+
| Unicode | Character Name |
+---------+-------------------------------------+
| 0621 | ARABIC LETTER HAMZA |
| 0622 | ARABIC LETTER ALEF WITH MADDA ABOVE |
| 0623 | ARABIC LETTER ALEF WITH HAMZA ABOVE |
| 0624 | ARABIC LETTER WAW WITH HAMZA ABOVE |
| 0625 | ARABIC LETTER ALEF WITH HAMZA BELOW |
| 0626 | ARABIC LETTER YEH WITH HAMZA ABOVE |
| 0627 | ARABIC LETTER ALEF |
| 0628 | ARABIC LETTER BEH |
| 0629 | ARABIC LETTER TEH MARBUTA |
| 062A | ARABIC LETTER TEH |
| 062B | ARABIC LETTER THEH |
| 062C | ARABIC LETTER JEEM |
| 062D | ARABIC LETTER HAH |
| 062E | ARABIC LETTER KHAH |
| 062F | ARABIC LETTER DAL |
| 0630 | ARABIC LETTER THAL |
| 0631 | ARABIC LETTER REH |
| 0632 | ARABIC LETTER ZAIN |
| 0633 | ARABIC LETTER SEEN |
| 0634 | ARABIC LETTER SHEEN |
| 0635 | ARABIC LETTER SAD |
| 0636 | ARABIC LETTER DAD |
| 0637 | ARABIC LETTER TAH |
| 0638 | ARABIC LETTER ZAH |
| 0639 | ARABIC LETTER AIN |
| 063A | ARABIC LETTER GHAIN |
| 0641 | ARABIC LETTER FEH |
| 0642 | ARABIC LETTER QAF |
| 0643 | ARABIC LETTER KAF |
| 0644 | ARABIC LETTER LAM |
| 0645 | ARABIC LETTER MEEM |
| 0646 | ARABIC LETTER NOON |
| 0647 | ARABIC LETTER HEH |
| 0648 | ARABIC LETTER WAW |
| 0649 | ARABIC LETTER ALEF MAKSURA |
| 064A | ARABIC LETTER YEH |
| 0660 | ARABIC-INDIC DIGIT ZERO |
| 0661 | ARABIC-INDIC DIGIT ONE |
| 0662 | ARABIC-INDIC DIGIT TWO |
| 0663 | ARABIC-INDIC DIGIT THREE |
| 0664 | ARABIC-INDIC DIGIT FOUR |
| 0665 | ARABIC-INDIC DIGIT FIVE |
| 0666 | ARABIC-INDIC DIGIT SIX |
| 0667 | ARABIC-INDIC DIGIT SEVEN |
| 0668 | ARABIC-INDIC DIGIT EIGHT |
| 0669 | ARABIC-INDIC DIGIT NINE |
+---------+-------------------------------------+

Source: Supporting the Arabic Language in Domain Names [10]
Table 1: CHARACTERS FROM UNICODE ARABIC TABLE (0600-06FF)

+---------+-----------------+
| Unicode | Digit Name |
+---------+-----------------+
| 0030 | DIGIT ZERO |
| 0031 | DIGIT ONE |
| 0032 | DIGIT TWO |
| 0033 | DIGIT THREE |
| 0034 | DIGIT FOUR |
| 0035 | DIGIT FIVE |
| 0036 | DIGIT SIX |
| 0037 | DIGIT SEVEN |
| 0038 | DIGIT EIGHT |
| 0039 | DIGIT NINE |
| 002D | HYPHEN-MINUS |
+---------+-----------------+

Source: Supporting the Arabic Language in Domain Names [11] [10]
Table 2: CHARACTERS FROM UNICODE BASIC LATIN TABLE (0000-007F)

2.3. Arabic Linguistic Issues Affected By Technical Constraints

In this section, technical aspects of some linguistic issues are
discussed.

2.3.1. Numerals

In the Arab countries, there are two sets of numerical digits used:

o Set I: (0, 1, 2, 3, 4, 5, 6, 7, 8, 9) mostly used in the western
part of the Arab world.

o Set II: (u+0660, u+0661, u+0662, u+0663, u+0664, u+0665, u+0666,
u+0667, u+0668, u+0669) mostly used in the eastern part of the
Arab world.

Both sets may be supported in the user interface; however, the rule
of numeral homogeneity must be observed. The rule specifies that
digits from the Arabic-Indic set of numerals (u+0660 to u+0669)
should not be allowed to mix with ASCII digits (u+0030 to u+0039)
within the same Arabic domain name label. Thus Thus, the appearance of a
digit from one set prevents the use of any other digit from the other
set.

2.3.2. The Space Character

The space character is strictly disallowed in domain names, as it is
a control character. Instead, the hyphen (Al-sharta) (i.e.u+02D) (Al-sharta, i.e., u+02D) is
proposed as a separator between Arabic words to avoid confusion that
can take place if the words are typed without a separator.

It is acceptable to use the hyphen to separate between words within
the same domain name label.

3. Summary and Conclusion

The proposed guidelines are in full accordance with the IETF IDN
standards and take into account Arabic language-specific Arabic-language-specific issues
within a compromise between grammatical rules of the Arabic language
and the ease of use of the that language on the Internet.

In summary, the guidelines specify that that, in Arabic domain names:

o Accent marks (Tashkeel and Shadda) are not permitted.

o Character folding is not permitted.

o If a numeral from the Arabic-Indic or ASCII digit sets appears in
a label, numeral homogeneity is required.

o The hyphen must be used as a word separator instead of space.

4. Security Considerations

No particular security considerations could be identified regarding
the use of Arabic characters in writing domain names. In particular,
any potential visual confusion between different character strings is
avoided using the guidelines proposed in this document.

5. IANA Considerations

This document has no action for IANA.

6. Acknowledgments

ESCWA ICT Division provided support and funding for the development
of this document with the objective of reaching a standard for a
comprehensive Arabic Domain Names. domain names. Thanks are due to SaudiNIC for
its continuous efforts in supporting the development of Arabic Domain
Names. domain
names.

John Klensin and Harald Alvestrand reviewed the document and provided
useful editorial and substantive support to enrich it.

6. References

7.1.

6.1. Normative References

[1] Faltstrom, P., Hoffman, P., and A. Costello,
"Internationalizing Domain Names in Applications (IDNA)", RFC
3490, March 2003.

[2] Hoffman, P. and M. Blanchet, "Nameprep: A Stringprep Profile
for Internationalized Domain Names (IDN)", RFC 3491, March
2003.

[3] Costello, A., "Punycode: A Bootstring encoding of Unicode for
Internationalized Domain Names in Applications (IDNA)", RFC
3492, March 2003.

[4] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.

7.2.

6.2. Informative References

[5] Klensin, J., "Internationalized Domain Names for Applications
(IDNA): Definitions, Background and Rationale",
draft-ietf-idnabis-rationale-06 (work Work in progress),
Progress, September 2008.

[6] Klensin, J., "Internationalized Domain Names in Applications
(IDNA): Protocol", draft-ietf-idnabis-protocol-08 (work Work in
progress), Progress, September 2008.

[7] Alvestrand, H. and C. Karp, "An updated IDNA criterion for
right-to-left scripts", draft-ietf-idnabis-bidi-03 (work Work in
progress), Progress, July 2008.

[8] Faltstrom, P., "The Unicode Codepoints and IDNA",
draft-ietf-idnabis-tables-05 (work Work in progress),
Progress, July 2008.

[9] United Nations Economic and Social Commission for Western Asia
(UN-ESCWA), "Guidelines for an Arabic Domain Name System
(ADNS)", Internet-Draft farah-adntf-adns-guidelines-03.txt, Work in Progress, November 2007.

[10] Al-Zoman, A., "Supporting the Arabic Language in Domain Names",
October 2003, <http://www.arabic-domains.org/docs/NIC-docs/
SupportingArabicDomainNmaes.pdf>. <http://www.arabic-domains.org/docs/
NIC-docs/SupportingArabicDomainNmaes.pdf>.

[11] Al-Zoman, A., "Arabic Top-Level Domains", July 2003. Paper presented in EGM
Expert Group Meeting on promotion Promotion of Digital Arabic Content,
the United Nations, ESCWA, Beirut Economic and Social Commission for Western
Asia, Beirut, June 2003.

[12] League of Arab States, "Report of the first meeting of AWG-ADN,
Damascus", February 2005,
<http://www.arabic-domains.org/ar/intrnational-entites.php>.

This document is in Arabic. <http://www.arabic-
domains.org/ar/intrnational-entites.php>.

Authors' Addresses

Ayman El-Sherbiny
Information and Communication Technology Division ESCWA
UN-House
P.O. Box 11-8575
Beirut
Lebanon

Email:

EMail: El-sherbiny@un.org

Mansour Farah
Information and Communication Technology Division ESCWA
UN-House
P.O. Box 11-8575
Beirut
Lebanon

Email:

EMail: farah14@un.org

Ibaa Oueichek
Syrian Telecom Establishment
Damascus
Syria

Email:

EMail: oueichek@scs-net.org

Abdulaziz H. Al-Zoman, PhD
SaudiNIC, General Directorate of Internet Services
IT Sector, CITC
King Abdulaziz City for Science and Technology
PO Box 6086
Riyadh 11442
Saudi Arabia

Email:

EMail: azoman@citc.gov.sa

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