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diff --git a/doc/rfc/rfc5645.txt b/doc/rfc/rfc5645.txt new file mode 100644 index 0000000..d270e0a --- /dev/null +++ b/doc/rfc/rfc5645.txt @@ -0,0 +1,731 @@ + + + + + + +Network Working Group D. Ewell, Ed. +Request for Comments: 5645 Consultant +Category: Informational September 2009 + + + Update to the Language Subtag Registry + +Abstract + + This memo defines the procedure used to update the IANA Language + Subtag Registry, in conjunction with the publication of RFC 5646, for + use in forming tags for identifying languages. + +Status of This Memo + + This memo provides information for the Internet community. It does + not specify an Internet standard of any kind. Distribution of this + memo is unlimited. + +Copyright Notice + + Copyright (c) 2009 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 in effect on the date of + publication of this document (http://trustee.ietf.org/license-info). + Please review these documents carefully, as they describe your rights + and restrictions with respect to this document. + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 + 2. Updating the Registry . . . . . . . . . . . . . . . . . . . . 2 + 2.1. Starting Point . . . . . . . . . . . . . . . . . . . . . . 2 + 2.2. New Language Subtags . . . . . . . . . . . . . . . . . . . 4 + 2.3. Modified Language Subtags . . . . . . . . . . . . . . . . 5 + 2.4. New Region Subtags . . . . . . . . . . . . . . . . . . . . 6 + 2.5. Grandfathered and Redundant Tags . . . . . . . . . . . . . 6 + 2.6. Preferred-Value Changes . . . . . . . . . . . . . . . . . 9 + 2.7. Additional Changes . . . . . . . . . . . . . . . . . . . . 9 + 3. Updated Registry Contents . . . . . . . . . . . . . . . . . . 10 + 4. Security Considerations . . . . . . . . . . . . . . . . . . . 10 + 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 + 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 + 6.1. Normative References . . . . . . . . . . . . . . . . . . . 11 + 6.2. Informative References . . . . . . . . . . . . . . . . . . 12 + Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 13 + + + +Ewell Informational [Page 1] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + +1. Introduction + + [RFC4646] provides for a Language Subtag Registry and describes its + format. The initial contents of the registry and rules for + determining them are specified in [RFC4645]. + + [RFC5646] expands on [RFC4646] by adding support for approximately + 7,500 new primary and extended language subtags based on [ISO639-3] + and [ISO639-5] alpha-3 code elements, and seven new region subtags + based on [ISO3166-1] exceptionally reserved code elements. This memo + describes the process of updating the registry to include these + additional subtags and to make secondary changes to the registry that + result from adding the new subtags and from other decisions made by + the Language Tag Registry Update (LTRU) Working Group. + + In writing this document, a complete replacement of the contents of + the Language Subtag Registry was provided to the Internet Assigned + Numbers Authority (IANA) to record the necessary updates. + + The format of the Language Subtag Registry as well as the definition + and intended purpose of each of the fields are described in + [RFC5646]. + + The registry is expected to change over time, as new subtags are + registered and existing subtags are modified or deprecated. The + process of updating the registry is described in Section 3 of + [RFC5646]. + + Many of the subtags defined in the Language Subtag Registry are based + on code elements defined in [ISO639-1], [ISO639-2], [ISO639-3], + [ISO639-5], [ISO3166-1], [ISO15924], and [UN_M.49]. The registry is + not a mirror of the code lists defined by these standards and should + not be used as one. + +2. Updating the Registry + + This section describes the process for determining the updated + contents of the Language Subtag Registry. + +2.1. Starting Point + + The version of the Language Subtag Registry that was current at the + time of IESG approval of this memo served as the starting point for + this update. This version was created according to the process + described in [RFC4645] and maintained according to the process + described in [RFC4646]. + + + + + +Ewell Informational [Page 2] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + + The source data for [ISO639-3] used for this update consisted of + three files, available from the official site of the ISO 639-3 + Registration Authority. (Note that this file is updated from time to + time. The version used in the preparation of this memo was the one + in place on February 24, 2009.) + + o [iso-639-3_20090210] is a list of all language code elements in + [ISO639-3], including the alpha-3 code element and reference name + for each code element. For example, the entry for the Dari + language contained the code element 'prs' and the name "Dari" + (among other information). + + o [iso-639-3_Name_Index_20090210] is a list containing all names + associated with each language according to [ISO639-3], including + both inverted and non-inverted forms where appropriate. An + "inverted" name is one that is altered from the usual English- + language order by moving adjectival qualifiers to the end, after + the main language name and separated by a comma. A code element + may have more than one entry in this file; the reference name and + its inverted form are usually, but not always, given in the first + entry. For example, this file contained an entry for the code + element 'prs' with the name "Dari" (twice) and another entry with + the names "Eastern Farsi" and "Farsi, Eastern". + + o [iso-639-3-macrolanguages_20090120] is a list of all alpha-3 code + elements for languages that are encompassed by a macrolanguage in + [ISO639-3], together with the alpha-3 code element for the + macrolanguage. For example, a line containing the code elements + 'fas' and 'prs' indicated that the macrolanguage "Persian" + encompasses the individual language "Dari". (Note that these + alpha-3 code elements may not have corresponded directly to + subtags in the registry, which uses 2-letter subtags derived from + [ISO639-1] when possible.) + + The source data for [ISO639-5] used for this update consisted of one + file, available from the official site of the ISO 639-5 Registration + Authority. (Note that this file is updated from time to time. The + version used in the preparation of this memo was the one in place on + February 24, 2009.) + + o [iso639-5.tab.txt] is a list of all language code elements in + [ISO639-5], including the alpha-3 code elements and English name + for each code element. For example, this file includes an entry + containing the code element 'ira' and the name "Iranian languages" + (among other information). + + + + + + +Ewell Informational [Page 3] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + + Language code elements that were already retired in all of the source + standards prior to IESG approval of this memo were not listed in + these files and, consequently, were not considered in this update. + + The values of the File-Date field, the Added date for each new subtag + record, and the Deprecated date for each existing grandfathered or + redundant tag deprecated by this update were set to a date as near as + practical to the date this memo was approved for publication by IESG. + +2.2. New Language Subtags + + For each language in [ISO639-3] that was not already represented by a + language subtag in the Language Subtag Registry, a new language + subtag was added to the registry, using the [ISO639-3] code element + as the value for the Subtag field and using each of the non-inverted + [ISO639-3] names as a separate Description field. The [ISO639-3] + reference name is represented by the first Description field. + + If the language was encompassed by one of the [ISO639-3] + macrolanguages 'ar' (Arabic), 'kok' (Konkani), 'ms' (Malay), 'sw' + (Swahili), 'uz' (Uzbek), or 'zh' (Chinese), as determined by + [iso-639-3-macrolanguages_20090120], an extended language subtag was + also added, with the primary language subtag of the macrolanguage as + the value for the Prefix field. These macrolanguage subtags were + already present in the Language Subtag Registry and were chosen + because they were determined by the LTRU Working Group to have been + used to represent a single dominant language as well as the + macrolanguage as a whole, making the extended language mechanism + suitable for languages encompassed by the macrolanguage. + + If the name of the language included the word "Sign", an extended + language subtag was added, with the string "sgn" as the value for the + Prefix field. This is a special case that treats the existing + primary language subtag for "Sign languages" as if it were a + macrolanguage encompassing all sign languages. + + All extended language subtags were added with a Preferred-Value equal + to the corresponding primary language subtag. + + If the language was encompassed by a macrolanguage, as determined by + [iso-639-3-macrolanguages_20090120], a Macrolanguage field was added + for the encompassed language, with a value equal to the subtag of the + macrolanguage. (Note that 'sgn' is defined as a "collection code" by + [ISO639-3] and hence is not included in that standard; therefore, no + Macrolanguage field was added for sign language subtags.) + + If the language was assigned a "Scope" value of 'M' (Macrolanguage) + in [iso-639-3_20090210], a Scope value of "macrolanguage" was added + + + +Ewell Informational [Page 4] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + + for the language. Otherwise, if the language was assigned a "Scope" + value of 'S' (Special), a Scope value of "special" was added. Most + languages in [ISO639-3] have scope 'I' (Individual) and thus were not + assigned a Scope value in the registry. + + For each language in [iso639-5.tab.txt] that was not already + represented by a language subtag in the Language Subtag Registry, a + new language subtag was added to the registry, using the [ISO639-5] + code element as the value for the Subtag field and using the "English + name" field as the Description field. Each of these languages was + assigned a Scope value of "collection" in the registry. + + All subtags were added to the registry maintaining alphabetical order + within each type of subtag: all 2-letter "language" subtags first, + then all 3-letter "language" subtags, and finally all "extlang" + subtags. Some existing records were moved to ensure this order. + +2.3. Modified Language Subtags + + For each language in [ISO639-3] that was already represented by a + language subtag in the Language Subtag Registry, Description fields + were added as necessary to reflect all non-inverted names listed for + that language in [iso-639-3_Name_Index_20090210]. Any existing + Description fields that reflected inverted names or that represented + a strict subset of the information provided by the [ISO639-3] name + were deleted. An example of the latter was the name "Ainu" for the + subtag 'ain', which provided less information than the [ISO639-3] + name "Ainu (Japan)". + + The order of Description fields was adjusted to ensure that the + reference name from [ISO639-3] was listed first, followed by other + names from [ISO639-3] in the order presented by that standard, + followed by any other names already existing in the registry. In + some cases, this resulted in a reordering of Description fields for + existing entries, even when no new values were added. + + For each language that was encompassed by a macrolanguage in + [ISO639-3], a Macrolanguage field was added, with a value equal to + the subtag of the macrolanguage. + + For each language in [iso639-5.tab.txt] that was already represented + in the Language Subtag Registry, the Description field was adjusted + as necessary to match the "English name" field in [iso639-5.tab.txt]. + Names in inverted form were rearranged to remove the inversion. Each + of these languages was assigned a Scope value of "collection". + Existing language subtags whose code elements were assigned prior to + the publication of [ISO639-3] or [ISO639-5] and that were identified + by the [ISO639-3] Registration Authority as representing collections + + + +Ewell Informational [Page 5] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + + were also assigned a Scope value of "collection", even though they + are not listed as such in [iso639-5.tab.txt]. + + Note in particular that the change from [ISO639-2] names such as + "Afro-Asiatic (Other)" to [ISO639-5] names such as "Afro-Asiatic + languages" implies a broadening of scope for some of these subtags, + designated "remainder groups" in [ISO639-5]. While + [iso639-5.tab.txt] includes a field indicating which code elements + are designated as "groups" or "remainder groups" in [ISO639-2], + [RFC5646] does not make this distinction, and consequently this field + was not used in updating the Language Subtag Registry. + + A Scope value of "private-use" was added for the unique record with + Subtag value 'qaa..qtz'. This record has a Description of "Private + use" (changed from "PRIVATE USE") and corresponds to a range of code + elements that is reserved for private use in [ISO639-2]. The + Description fields for script and region private-use subtags were + also capitalized as "Private use". + +2.4. New Region Subtags + + [RFC5646] expands the scope of region subtags by adding subtags based + on code elements defined as "exceptionally reserved" in [ISO3166-1]. + These code elements are reserved by the ISO 3166 Maintenance Agency + "at the request of national ISO member bodies, governments and + international organizations". At the time of IESG approval of this + memo, ISO 3166/MA had defined nine exceptionally reserved code + elements, all of which were added to the Language Subtag Registry + except for the following: + + o 'FX' (Metropolitan France) was already present in the Language + Subtag Registry because it was an assigned [ISO3166-1] code + element from 1993 to 1997, but was deprecated with a Preferred- + Value of "FR". + + o 'UK' (United Kingdom) was not added because it is associated with + the same UN M.49 code (826) as the existing region subtag 'GB'. + [RFC5646], Section 3.4, item 15 (D) states that a new region + subtag is not added to the Language Subtag Registry if it carries + the same meaning as an existing region subtag. + +2.5. Grandfathered and Redundant Tags + + As stated in [RFC5646], "grandfathered" and "redundant" tags are + complete tags in the Language Subtag Registry that were registered + under [RFC1766] or [RFC3066] and remain valid. Grandfathered tags + cannot be generated from a valid combination of subtags, while + redundant tags can be. + + + +Ewell Informational [Page 6] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + + Under certain conditions, registration of a subtag under [RFC5646] + may cause a grandfathered tag to be reclassified as redundant. It + may also enable the creation of a generative tag with the same + meaning as a grandfathered or redundant tag; in that case, the + grandfathered or redundant tag is marked as Deprecated, and the + generative tag (including the new subtag) becomes its Preferred- + Value. + + As a result of adding the new subtags in this update, each of the + following grandfathered tags became composable, were reclassified as + redundant, and were deprecated with the indicated generative tag + serving as the Preferred-Value: + + zh-cmn (Preferred-Value: cmn) + + zh-cmn-Hans (Preferred-Value: cmn-Hans) + + zh-cmn-Hant (Preferred-Value: cmn-Hant) + + zh-gan (Preferred-Value: gan) + + zh-wuu (Preferred-Value: wuu) + + zh-yue (Preferred-Value: yue) + + The following grandfathered tags were deprecated, with the indicated + generative tag serving as the Preferred-Value: + + i-ami (Preferred-Value: ami) + + i-bnn (Preferred-Value: bnn) + + i-pwn (Preferred-Value: pwn) + + i-tao (Preferred-Value: tao) + + i-tay (Preferred-Value: tay) + + i-tsu (Preferred-Value: tsu) + + zh-hakka (Preferred-Value: hak) + + zh-min (no Preferred-Value; see below) + + zh-min-nan (Preferred-Value: nan) + + zh-xiang (Preferred-Value: hns) + + + + +Ewell Informational [Page 7] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + + The tag "zh-min", originally registered under [RFC1766], is a special + case: it represents a small class of Chinese languages, but is not a + true macrolanguage. The string "min" could not ever be used to tag + these languages since the [ISO639-3] code element 'min' is assigned + to an individual language (Minangkabau) that is not related to + Chinese ('zh'). Because it is not believed to represent a useful + linguistic entity for tagging purposes, it was deprecated without a + Preferred-Value. + + The following grandfathered and redundant sign language tags were + deprecated, with the indicated generative tag serving as the + Preferred-Value: + + sgn-BE-FR (Preferred-Value: sfb) + + sgn-BE-NL (Preferred-Value: vgt) + + sgn-BR (Preferred-Value: bzs) + + sgn-CH-DE (Preferred-Value: sgg) + + sgn-CO (Preferred-Value: csn) + + sgn-DE (Preferred-Value: gsg) + + sgn-DK (Preferred-Value: dsl) + + sgn-ES (Preferred-Value: ssp) + + sgn-FR (Preferred-Value: fsl) + + sgn-GB (Preferred-Value: bfi) + + sgn-GR (Preferred-Value: gss) + + sgn-IE (Preferred-Value: isg) + + sgn-IT (Preferred-Value: ise) + + sgn-JP (Preferred-Value: jsl) + + sgn-MX (Preferred-Value: mfs) + + sgn-NI (Preferred-Value: ncs) + + sgn-NL (Preferred-Value: dse) + + sgn-NO (Preferred-Value: nsl) + + + +Ewell Informational [Page 8] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + + sgn-PT (Preferred-Value: psr) + + sgn-SE (Preferred-Value: swl) + + sgn-US (Preferred-Value: ase) + + sgn-ZA (Preferred-Value: sfs) + + No change was made to the Description field(s) for any of the + grandfathered or redundant tags. For example, the redundant tag + "sgn-US" continues to carry the Description "American Sign Language". + The sign language tags registered prior to [RFC4646] remain an + exception to the general principle that the meaning of a non- + grandfathered tag can be derived from its component subtags. + + In previous versions of the registry, grandfathered tags that had + been deprecated as a result of adding an ISO 639-based language + subtag included a Comments field, with a value of the form "replaced + by ISO code xxx", where 'xxx' represented the new language subtag. + These comments duplicated the information contained within the + Preferred-Value field and were deleted as part of this update. No + changes were made to other Comments fields. + +2.6. Preferred-Value Changes + + [RFC5646], Section 3.1.7 provides for the value of Preferred-Value + fields to be updated as necessary to reflect changes in one of the + source standards. Accordingly, the Preferred-Value fields for the + following deprecated tags were changed: + + i-hak (changed from zh-hakka to hak) + + zh-guoyu (changed from zh-cmn to cmn) + + This makes it unnecessary for consumers of the Language Subtag + Registry to follow a "chain" of Preferred-Values in order to arrive + at a non-deprecated subtag. + +2.7. Additional Changes + + For consistency with the handling of alternative names in language + subtags, Description fields for script subtags taken from [ISO15924] + that represent alternative names were converted to multiple + Description fields. For example, the Description "Han (Hanzi, Kanji, + Hanja)" was converted to four separate Description fields. Some + Description fields for script subtags contained parenthetical + material that was explanatory, rather than identifying alternative + names; these fields were not altered. + + + +Ewell Informational [Page 9] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + + This situation does not apply to region subtags taken from + [ISO3166-1] and [UN_M.49] because those standards do not provide + freely available alternative names for code elements. + + Description fields in inverted form for script and region subtags + were rearranged to remove the inversion, for consistency with the + handling of language subtags in Sections 2.2 and 2.3. For example, + the Description field "Korea, Republic of" was changed to "Republic + of Korea". + + The capitalization of the Subtag fields for certain grandfathered and + redundant tags (sgn-BE-fr, sgn-BE-nl, sgn-CH-de, and yi-latn) was + modified to conform with the capitalization conventions described in + [RFC5646], Section 2.1.1. This has no effect on the validity or + meaning of these tags. + + The Description field for subtag 'sgn' was capitalized as "Sign + languages" to match the capitalization used for other languages in + [ISO639-5], even though this capitalization does not exactly match + that used for code element 'sgn' in any of the ISO 639 parts. + + The Deprecated field for the region subtag TP was modified from 2002- + 11-15 to 2002-05-20, to correct a clerical error. The corrected date + reflects the actual date the code element TP was withdrawn in + [ISO3166-1]. + + The order of fields within records in the registry was adjusted as + necessary to match the order in which these fields are described in + [RFC5646], Section 3.1.2. This ordering is not required by [RFC5646] + and may not necessarily be reflected in future additions or + modifications to the registry. + +3. Updated Registry Contents + + IANA has updated the Language Subtag Registry according to the + provided replacement contents. The replacement content was listed in + the working draft of this document, but was deleted prior to + publication as an RFC to avoid potential confusion with the registry + itself. The Language Subtag Registry is available from the IANA + website, <http://www.iana.org>. + +4. Security Considerations + + For security considerations relevant to the Language Subtag Registry + and the use of language tags, see [RFC5646]. + + + + + + +Ewell Informational [Page 10] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + +5. IANA Considerations + + IANA has updated the Language Subtag Registry, which can be found via + <http://www.iana.org>. For details on the procedures for the format + and ongoing maintenance of this registry, see RFC 5646. + +6. References + +6.1. Normative References + + [ISO639-3] International Organization for Standardization, "ISO 639- + 3:2007. Codes for the representation of names of + languages - Part 3: Alpha-3 code for comprehensive + coverage of languages", February 2007. + + [ISO639-5] International Organization for Standardization, "ISO 639- + 5:2008. Codes for the representation of names of + languages -- Part 5: Alpha-3 code for language families + and groups", May 2008. + + [RFC5646] Phillips, A., Ed. and M. Davis, Ed., "Tags for + Identifying Languages", RFC 5646, September 2009. + + [iso-639-3-macrolanguages_20090120] + International Organization for Standardization, "ISO + 639-3 Macrolanguage Mappings", January 2009, <http:// + www.sil.org/iso639-3/ + iso-639-3-macrolanguages_20090120.tab>. + + [iso-639-3_20090210] + International Organization for Standardization, "ISO + 639-3 Code Set", February 2009, + <http://www.sil.org/iso639-3/iso-639-3_20090210.tab>. + + [iso-639-3_Name_Index_20090210] + International Organization for Standardization, "ISO + 639-3 Language Names Index", February 2009, + <http://www.sil.org/ + iso639-3/iso-639-3_Name_Index_20090210.tab>. + + [iso639-5.tab.txt] + International Organization for Standardization, "ISO + 639-5 code list, Tab-delimited text", February 2009, + <http://www.loc.gov/standards/iso639-5/iso639-5.tab.txt>. + + + + + + + +Ewell Informational [Page 11] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + +6.2. Informative References + + [ISO15924] International Organization for Standardization, "ISO + 15924:2004. Information and documentation -- Codes for + the representation of names of scripts", January 2004. + + [ISO3166-1] International Organization for Standardization, "ISO + 3166- 1:2006. Codes for the representation of names of + countries and their subdivisions -- Part 1: Country + codes", November 2006. + + [ISO639-1] International Organization for Standardization, "ISO 639- + 1:2002. Codes for the representation of names of + languages -- Part 1: Alpha-2 code", July 2002. + + [ISO639-2] International Organization for Standardization, "ISO 639- + 2:1998. Codes for the representation of names of + languages -- Part 2: Alpha-3 code", October 1998. + + [RFC1766] Alvestrand, H., "Tags for the Identification of + Languages", RFC 1766, March 1995. + + [RFC3066] Alvestrand, H., "Tags for the Identification of + Languages", RFC 3066, January 2001. + + [RFC4645] Ewell, D., "Initial Language Subtag Registry", RFC 4645, + September 2006. + + [RFC4646] Phillips, A. and M. Davis, "Tags for Identifying + Languages", BCP 47, RFC 4646, September 2006. + + [UN_M.49] Statistics Division, United Nations, "Standard Country or + Area Codes for Statistical Use", Revision 4 (United + Nations publication, Sales No. 98.XVII.9, June 1999. + + + + + + + + + + + + + + + + + +Ewell Informational [Page 12] + +RFC 5645 Update to the Language Subtag Registry September 2009 + + +Appendix A. Acknowledgements + + This memo is a collaborative work of the Language Tag Registry Update + (LTRU) Working Group. All of its members have made significant + contributions to this memo and to its predecessor, [RFC4645]. + + Specific contributions to this memo were made by Stephane Bortzmeyer, + John Cowan, Mark Davis, Martin Duerst, Frank Ellermann, Debbie + Garside, Kent Karlsson, Gerard Lang, Addison Phillips, Randy Presuhn, + and CE Whitehead. + +Author's Address + + Doug Ewell (editor) + Consultant + + EMail: doug@ewellic.org + URI: http://www.ewellic.org + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Ewell Informational [Page 13] + |