Content Language Headers (RFC3282)
Original Publication Date: 2002-May-01
Included in the Prior Art Database: 2002-May-30
Internet Society Requests For Comment (RFCs)
This document defines a "Content-language:" header, for use in cases where one desires to indicate the language of something that has RFC 822-like headers, like MIME body parts or Web documents, and an "Accept-Language:" header for use in cases where one wishes to indicate one's preferences with regard to language.
Network Working Group H. Alvestrand
Request for Comments: 3282 Cisco Systems
Obsoletes: 1766 May 2002
Category: Standards Track
Content Language Headers
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright (C) The Internet Society (2002). All Rights Reserved.
This document defines a "Content-language:" header, for use in cases
where one desires to indicate the language of something that has RFC
822-like headers, like MIME body parts or Web documents, and an
"Accept-Language:" header for use in cases where one wishes to
indicate one's preferences with regard to language.
There are a number of languages presently or previously used by human
beings in this world.
A great number of these people would prefer to have information
presented in a language which they understand.
In some contexts, it is possible to have information available in
more than one language, or it might be possible to provide tools
(such as dictionaries) to assist in the understanding of a language.
In other cases, it may be desirable to use a computer program to
convert information from one format (such as plaintext) into another
(such as computer-synthesized speech, or Braille, or high-quality
Alvestrand Standards Track [Page 1]
RFC 3282 Content Language Headers May 2002
A prerequisite for any such function is a means of labelling the
information content with an identifier for the language that is used
in this information content, such as is defined by [TAGS]. This
document specifies a protocol element for use with protocols that use
RFC 822-like headers for carrying language tags as defined in [TAGS].
The keywords "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].
2. The Content-language header
The "Content-Language" header is intended for use in the case where
one desires to indicate the language(s) of something that has RFC
822-like headers, such as MIME body parts or Web documents.
The RFC 822 EBNF of the Content-Language header is:
Content-Language = "Content-Language" ":" 1#Language-tag
In the more strict RFC 2234 ABNF:
Content-Language = "Content-Language" ":" [CFWS] Language-List
Language-List = Language-Tag [CFWS]
*("," [CFWS] Language-Tag [CFWS])
The Content-Language header may list several languages in a comma-
The CFWS construct is intended to function like the whitespace
convention in RFC 822, which means also that one can place
parenthesized comments anywhere in the language sequence, or use
continuation lines. A formal definition is given in RFC 282...