preferred_charset specifies the character set in MIME notation (e.g.,
ISO-8859-2, ISO-8859-5) which Lynx will indicate you prefer in requests
to http servers using an Accept-Charset header. The value should NOT
include ISO-8859-1 or US-ASCII, since those values are always assumed
by default. May be a comma-separated list.
If a file in that character set is available, the server will send it.
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, though the sending of an unacceptable response
is also allowed.