RFC 3282 (rfc3282) - Page 2 of 8

Content Language Headers

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-
   separated list.

   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 2822
   [RFC 2822].

   In keeping with the tradition of RFC 2822, a more liberal "obsolete"
   grammar is also given:

      obs-content-language = "Content-Language" *WSP ":"
                              [CFWS] Language-List

   Like RFC 2822, this specification says that conforming
   implementations MUST accept the obs-content-language syntax, but MUST
   NOT generate it; all generated headers MUST conform to the Content-
   Language syntax.






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