14.2 Accept-Charset


The Accept-Charset request-header field can be used to indicate what character sets are acceptable for the response. This field allows clients capable of understanding more comprehensive or special- purpose character sets to signal that capability to a server which is capable of representing documents in those character sets.
      Accept-Charset = "Accept-Charset" ":"
              1#( ( charset | "*" )[ ";" "q" "=" qvalue ] )


Character set values are described in section 3.4. Each charset MAY be given an associated quality value which represents the user's preference for that charset. The default value is q=1. An example is
      Accept-Charset: iso-8859-5, unicode-1-1;q=0.8


The special value "*", if present in the Accept-Charset field, matches every character set (including ISO-8859-1) which is not mentioned elsewhere in the Accept-Charset field. If no "*" is present in an Accept-Charset field, then all character sets not explicitly mentioned get a quality value of 0, except for ISO-8859-1, which gets a quality value of 1 if not explicitly mentioned.

If no Accept-Charset header is present, the default is that any character set is acceptable. If an Accept-Charset header is present, and if the server cannot send a response which is acceptable according to the Accept-Charset header, then the server SHOULD send an error response with the 406 (not acceptable) status code, though the sending of an unacceptable response is also allowed.