BCP 47 Extension U
RFC 6067
| Document | Type |
RFC - Informational
(December 2010; No errata)
Was draft-davis-u-langtag-ext (individual in app area)
|
|
|---|---|---|---|
| Last updated | 2020-07-29 | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 6067 (Informational) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Alexey Melnikov | ||
| Send notices to | (None) | ||
Internet Engineering Task Force (IETF) M. Davis
Request for Comments: 6067 Google
Category: Informational A. Phillips
ISSN: 2070-1721 Lab126
Y. Umaoka
IBM
December 2010
BCP 47 Extension U
Abstract
This document specifies an Extension to BCP 47 that provides subtags
that specify language and/or locale-based behavior or refinements to
language tags, according to work done by the Unicode Consortium.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are 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/rfc6067.
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. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Davis, et al. Informational [Page 1]
RFC 6067 BCP 47 Unicode Locale Extension December 2010
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . . 2
2. BCP 47 Required Information . . . . . . . . . . . . . . . . . . 2
2.1. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.1. Canonicalization . . . . . . . . . . . . . . . . . . . 5
2.2. Registration Form . . . . . . . . . . . . . . . . . . . . . 6
3. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 7
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.1. Normative References . . . . . . . . . . . . . . . . . . . 7
6.2. Informative References . . . . . . . . . . . . . . . . . . 7
1. Introduction
[BCP47] permits the definition and registration of language tag
extensions "that contain a language component and are compatible with
applications that understand language tags". This document defines
an extension for identifying Unicode locale-based variations using
language tags. The "singleton" identifier for this extension is 'u'.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. BCP 47 Required Information
Language tags, as defined by [BCP47], are useful for identifying the
language of content. They are also used as locale identifiers (or
can be mapped to locales) in many operating environments and APIs.
However, many locale identifiers also require additional "tailorings"
or options for specific values within a language, culture, region, or
other variation. This extension provides a mechanism for using these
additional tailorings within language tags for general interchange.
The Unicode Consortium defines a standardized, structured set of
locale data and identifiers for locale data in the "Common Locale
Data Repository" or "CLDR". The maintaining authority for the
extension defined by this document is the Unicode Consortium:
Davis, et al. Informational [Page 2]
RFC 6067 BCP 47 Unicode Locale Extension December 2010
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