Network Working Group G. Klyne
Internet-Draft MIMEsweeper Group
Expires: May 7, 2002 Nov 6, 2001
A URN sub-namespace for language tags
draft-klyne-urn-ietf-lang-01
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on May 7, 2002.
Copyright Notice
Copyright (C) The Internet Society (2001). All Rights Reserved.
Abstract
This specification defines a form of URN to be used for language tags
defined or registered according to RFC 3066. The URN namespace used
is 'ietf', defined by RFC 2648 and extended by RFC????.
Klyne Expires May 7, 2002 [Page 1]
Internet-Draft URNs for language tags Nov 2001
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Registration template . . . . . . . . . . . . . . . . . . . . 3
3. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. IANA considerations . . . . . . . . . . . . . . . . . . . . . 4
5. Security considerations . . . . . . . . . . . . . . . . . . . 5
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5
References . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . 6
A. Revision history . . . . . . . . . . . . . . . . . . . . . . . 6
A.1 draft-klyne-urn-ietf-lang-00 . . . . . . . . . . . . . . . . . 6
A.2 Todo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Full Copyright Statement . . . . . . . . . . . . . . . . . . . 7
Klyne Expires May 7, 2002 [Page 2]
Internet-Draft URNs for language tags Nov 2001
1. Introduction
This specification defines a form of URN to be used for language tags
defined or registered according to RFC 3066 [4]. The URN namespace
used is 'IETF', defined by RFC 2648 [3] and extended by RFC???? [7]
to include names for IETF protocol parameters.
1.1 Background
RFC 3066 [4] defines a construction and registry for tags used to
identify human languages. These tags can be used to describe the
language used by human-readable text, or other data intended for
human prsentation.
There are situations in which it is desired to express a language tag
in the form of a URI, but no definitive URI form has been defined.
For example, W3C has defined RDF [5], a generic XML-based metadata
format that uses URIs to identify objects and the relationships
between them. There has been some requirement to use language tags
with RDF. RFC 3066 language tags have the desired semantics, but it
is not clear how they should be represented in RDF. The normal form
of identification used by RDF (and the Web in general) is a URI or
URI-reference as defined by RFC 2396 [2].
This specification defines a way to embed RFC 3066 language tags in a
urn: form of URI, which can be used to identify a language in
contexts where a URI is prefered to a text string or token.
2. Registration template
The URN sub-namespace for language tags is defined as follows.
Registry name:
language
Specification:
RFC 3066 [4].
Repository:
http://www.iana.org/assignments/language-tags
See also non-registered language tags defined by RFC 3066 [4].
Index value:
The language tag name is the registry index value. RFC 3066
allows this tag name to contain uppercase letters, lowercase
letters, digits, and dash ("-"). Language tags are case-
insensitive.
Klyne Expires May 7, 2002 [Page 3]
Some allowed unregistered language tag values are defined by
reference to ISO standard 639 [6].
URN formation:
The URN for a language tag is formed as:
"urn:ietf:params:language:<tag-name>", where <tag-name> is the
language registry index value, expressed using lower case letters.
RFC 2141 [1] defines the format of URNs. Allowable characters
include all of those noted above.
URNs are defined by RFC 2141 [1] as lexically equivalent if they
are identical following case normalization of the urn scheme name,
the namespace name and any %-escaping used. Language tags are
defined such that upper- and lower-case ASCII characters are not
distinguished. In forming a URN, all ASCII characters in the
language tag must be expressed in lower case.
3. Examples
This table lists some language tags, and the corresponding urn: URIs.
MN (Mongolian)
urn:ietf:params:language:mn
en-US (American English)
urn:ietf:params:language:en-us
zh-yue (Cantonese)
urn:ietf:params:language:zh-yue
sgn-GB (British sign language)
urn:ietf:params:language:sgn-gb
i-klingon
urn:ietf:params:language:i-klingon
i-default
urn:ietf:params:language:i-default
x-private
urn:ietf:params:language:x-private
4. IANA considerations
This document calls for the creation of a new IETF sub-namespace per
RFC???? [7]. Registration details are in the preceding section.
Klyne Expires May 7, 2002 [Page 4]
Internet-Draft URNs for language tags Nov 2001
5. Security considerations
No security considerations are introduced by this specification
beyond those already inherrent in the use of language tags [4].
6. Acknowledgements
The author gratefully acknowledges the contributions of: Martyn
Horner, [[[...]]]
References
[1] Moats, R., "URN Syntax", RFC 2141, May 1997.
[2] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource
Identifiers (URI): Generic Syntax", RFC 2396, August 1998.
[3] Moats, R., "A URN Namespace for IETF Documents", RFC 2648,
August 1999.
[4] Alvestrand, H., "Tags for the Identification of Languages", BCP
47, RFC 3066, January 2001.
[5] Lassila, O. and R. Swick, "Resource Description Framework (RDF)
Model and Syntax Specification", W3C Recommendation rdf-syntax,
February 1999, <http://www.w3.org/TR/REC-rdf-syntax>.
[6] International Organization for Standardization, "Code for the
representation of names of languages, 1st edition", ISO Standard
639, 1988.
[7] Mealling, M., Masinter, L., Hardie, T. and G. Klyne, "An IETF
URN Sub-namespace for Registered Protocol Parameters", Internet
draft draft-mealling-iana-urn-02, August 2001,
<http://search.ietf.org/internet-drafts/draft-mealling-iana-urn-
02.txt>.
Klyne Expires May 7, 2002 [Page 5]
Internet-Draft URNs for language tags Nov 2001
Author's Address
Graham Klyne
MIMEsweeper Group
1310 Waterside
Arlington Business Park
Theale, Reading RG7 4SA
UK
Phone: +44 118 903 8000
Fax: +44 118 903 9000
EMail: Graham.Klyne@MIMEsweeper.com
Appendix A. Revision history
[[[This section to be removed on final publication]]]
A.1 draft-klyne-urn-ietf-lang-00
00a 18-Sep-2001: document initially created.
00b 24-Sep-2001: Small editorial fixes.
01a 06-Nov-2001: Revise background material. Editorial fixes.
A.2 Todo
o Align with urn:ietf:params: draft as it develops.
o Replace RFC???? with appropriate RFC numbers, when issued.
o Remove [[[editorial comments]]].
Klyne Expires May 7, 2002 [Page 6]
Internet-Draft URNs for language tags Nov 2001
Full Copyright Statement
Copyright (C) The Internet Society (2001). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
Klyne Expires May 7, 2002 [Page 7]