Re: [whatwg] several messages about content sniffing in HTML

[Boris Zbarsky]

Geoffrey Sneddon wrote:
Content-Type: XML
Content-Type: text/XML
Using the first would break badly. I guess it seems to work because of 
content-type sniffing on an unknown (and invalid) header

Or because the header parser uses the first header that actually looks like a 
valid content-type (e.g. contains a '/').  Specifying this _is_ needed.

-Boris