doc: Add RFC documents

1 files changed, 619 insertions, 0 deletions

diff --git a/doc/rfc/rfc5564.txt b/doc/rfc/rfc5564.txt
new file mode 100644
index 0000000..d9b413a
--- /dev/null
+++ b/doc/rfc/rfc5564.txt
@@ -0,0 +1,619 @@
+
+
+
+
+
+
+Independent Submission                                    A. El-Sherbiny
+Request for Comments: 5564                                      M. Farah
+Category: Informational                                         UN-ESCWA
+ISSN: 2070-1721                                              I. Oueichek
+                                            Syrian Telecom Establishment
+                                                             A. Al-Zoman
+                                                          SaudiNIC, CITC
+                                                           February 2010
+
+
+                  Linguistic Guidelines for the Use of
+                the Arabic Language in Internet Domains
+
+Abstract
+
+   This document constitutes technical specifications for the use of
+   Arabic in Internet domain names and provides linguistic guidelines
+   for Arabic domain names.  It addresses Arabic-specific linguistic
+   issues pertaining to the use of Arabic language in domain names.
+
+Status of This Memo
+
+   This document is not an Internet Standards Track specification; it is
+   published for informational purposes.
+
+   This is a contribution to the RFC Series, independently of any other
+   RFC stream.  The RFC Editor has chosen to publish this document at
+   its discretion and makes no statement about its value for
+   implementation or deployment.  Documents approved for publication by
+   the RFC Editor are not a candidate for any level of Internet
+   Standard; see Section 2 of RFC 5741.
+
+   Information about the current status of this document, any errata,
+   and how to provide feedback on it may be obtained at
+   http://www.rfc-editor.org/info/rfc5564.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+El-Sherbiny, et al.           Informational                     [Page 1]
+
+RFC 5564               Arabic Character Guidelines         February 2010
+
+
+Copyright Notice
+
+   Copyright (c) 2010 IETF Trust and the persons identified as the
+   document authors.  All rights reserved.
+
+   This document is subject to BCP 78 and the IETF Trust's Legal
+   Provisions Relating to IETF Documents
+   (http://trustee.ietf.org/license-info) in effect on the date of
+   publication of this document.  Please review these documents
+   carefully, as they describe your rights and restrictions with respect
+   to this document.
+
+   This document may not be modified, and derivative works of it may not
+   be created, except to format it for publication as an RFC or to
+   translate it into languages other than English.
+
+Table of Contents
+
+   1. Introduction ....................................................2
+   2. Arabic Language-Specific Issues .................................3
+      2.1. Linguistic Issues ..........................................4
+           2.1.1. Diacritics (Tashkeel) and Shadda ....................4
+           2.1.2. Kasheeda or Tatweel (Horizontal Character
+                  Size Extension) .....................................5
+           2.1.3. Character Folding ...................................5
+      2.2. Supported Character Set ....................................6
+      2.3. Arabic Linguistic Issues Affected by Technical
+           Constraints ................................................8
+           2.3.1. Numerals ............................................8
+           2.3.2. The Space Character .................................8
+   3. Summary and Conclusion ..........................................8
+   4. Security Considerations .........................................9
+   5. Acknowledgments .................................................9
+   6. References ......................................................9
+      6.1. Normative References .......................................9
+      6.2. Informative References .....................................9
+
+1.  Introduction
+
+   The Internet Engineering Task Force (IETF) issued in March 2003 a set
+   of RFCs for Internationalized Domain Names (IDN) ([1], [2], and [3]),
+   which were planned to become the de facto standard for all languages.
+   In 2007 and 2008, the following working drafts were released that
+   propose revisions to the IDNA protocol:
+
+   o  Internationalized Domain Names for Applications (IDNA):
+      Background, Explanation, and Rationale [5]
+
+
+
+
+El-Sherbiny, et al.           Informational                     [Page 2]
+
+RFC 5564               Arabic Character Guidelines         February 2010
+
+
+   o  Internationalized Domain Names in Applications (IDNA): Protocol
+      [6]
+
+   o  An updated IDNA criterion for right-to-left scripts [7]
+
+   o  The Unicode code points and IDNA [8]
+
+   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.  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), 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 on
+   that group's document, "Guidelines for an Arabic Internet Domain
+   Name" [9].  This document is also in full harmony with recent
+   rigorous discussions that took place within the major language
+   communities that use the Arabic script in their languages.
+
+   This document provides guidelines for the ways Arabic characters may
+   be used for registering Internet domain names and how 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 is to have
+   a vehicle to increase Internet use amongst all strata of the Arabic-
+   speaking communities.
+
+   Furthermore, a 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
+
+
+
+
+El-Sherbiny, et al.           Informational                     [Page 3]
+
+RFC 5564               Arabic Character Guidelines         February 2010
+
+
+   Internet and leading to further isolation of these communities at the
+   global level.
+
+   Hence, there have been intensive efforts (especially those
+   spearheaded by Dr. Al-Zoman and contributed to by UN-ESCWA and its
+   Arabic Domain Names Task Force (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, 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 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] and [11]) and on the report of the first
+   meeting of AWG-ADN [12].  For details, the reader is encouraged to
+   review these references.
+
+2.1.1.  Diacritics (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
+
+
+
+
+El-Sherbiny, et al.           Informational                     [Page 4]
+
+RFC 5564               Arabic Character Guidelines         February 2010
+
+
+   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
+
+   o  Folding different forms of Hamzah (U+0622, U+0623, U+0625, U+0627)
+
+   o  Folding Alef Maksura (U+0649) and Yeh (U+064A) at the end of a
+      word
+
+   o  Folding Waw with Hamzah Above (U+0624) and Waw (U+0648)
+
+   With respect to the Arabic language, character folding is not
+   acceptable because it changes the meaning of words and 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 only one word representing several words consisting
+
+
+
+
+El-Sherbiny, et al.           Informational                     [Page 5]
+
+RFC 5564               Arabic Character Guidelines         February 2010
+
+
+   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, 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, 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 effect on the principle and ethics of the language.
+   Technology should work to preserve the language and not 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
+   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 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                   |
+
+
+
+El-Sherbiny, et al.           Informational                     [Page 6]
+
+RFC 5564               Arabic Character Guidelines         February 2010
+
+
+             | 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 [10]
+      Table 2: CHARACTERS FROM UNICODE BASIC LATIN TABLE (0000-007F)
+
+
+
+
+
+El-Sherbiny, et al.           Informational                     [Page 7]
+
+RFC 5564               Arabic Character Guidelines         February 2010
+
+
+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, 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) 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 issues
+   within a compromise between grammatical rules of the Arabic language
+   and ease of use of that language on the Internet.
+
+   In summary, the guidelines specify that, in Arabic domain names:
+
+   o  Accent marks (Tashkeel and Shadda) are not permitted.
+
+   o  Character folding is not permitted.
+
+
+
+
+
+El-Sherbiny, et al.           Informational                     [Page 8]
+
+RFC 5564               Arabic Character Guidelines         February 2010
+
+
+   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.  Acknowledgments
+
+   ESCWA ICT Division provided support and funding for the development
+   of this document with the objective of reaching a standard for
+   comprehensive Arabic domain names.  Thanks are due to SaudiNIC for
+   its continuous efforts in supporting the development of Arabic domain
+   names.
+
+   John Klensin and Harald Alvestrand reviewed the document and provided
+   useful editorial and substantive support to enrich it.
+
+6.  References
+
+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.
+
+6.2.  Informative References
+
+   [5]   Klensin, J., "Internationalized Domain Names for Applications
+         (IDNA): Definitions, Background and Rationale", Work in
+         Progress, September 2008.
+
+
+
+
+El-Sherbiny, et al.           Informational                     [Page 9]
+
+RFC 5564               Arabic Character Guidelines         February 2010
+
+
+   [6]   Klensin, J., "Internationalized Domain Names in Applications
+         (IDNA): Protocol", Work in Progress, September 2008.
+
+   [7]   Alvestrand, H. and C. Karp, "An updated IDNA criterion for
+         right-to-left scripts", Work in Progress, July 2008.
+
+   [8]   Faltstrom, P., "The Unicode Codepoints and IDNA", Work in
+         Progress, July 2008.
+
+   [9]   United Nations Economic and Social Commission for Western Asia
+         (UN-ESCWA), "Guidelines for an Arabic Domain Name System
+         (ADNS)", 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>.
+
+   [11]  Al-Zoman, A., "Arabic Top-Level Domains", Paper presented in
+         Expert Group Meeting on Promotion of Digital Arabic Content,
+         the United Nations, 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>.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+El-Sherbiny, et al.           Informational                    [Page 10]
+
+RFC 5564               Arabic Character Guidelines         February 2010
+
+
+Authors' Addresses
+
+   Ayman El-Sherbiny
+   Information and Communication Technology Division ESCWA
+   UN-House
+   P.O. Box 11-8575
+   Beirut
+   Lebanon
+
+   EMail: El-sherbiny@un.org
+
+
+   Mansour Farah
+   Information and Communication Technology Division ESCWA
+   UN-House
+   P.O. Box 11-8575
+   Beirut
+   Lebanon
+
+   EMail: farah14@un.org
+
+
+   Ibaa Oueichek
+   Syrian Telecom Establishment
+   Damascus
+   Syria
+
+   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: azoman@citc.gov.sa
+
+
+
+
+
+
+
+
+
+
+
+
+El-Sherbiny, et al.           Informational                    [Page 11]
+