For HTTP responses with Content-Types suggesting character data, which charset should be assumed by the client if none is specified?

Question

If no charset parameter is specified in the Content-Type header, RFC2616 section 3.7.1 seems to imply ISO8859-1 should be assumed for media types of subtype "text":

Answer 1

It's a bit special for XMLHttpRequest and is described here: http://www.w3.org/TR/XMLHttpRequest/