RFC2068 question : is Content-Type mandatory ?

Hello,

I've run into a webserver ( www.bea.com ) that does not send the
Content-Type headerline back. Default behaviour of the proxy code is to
add "Content-Type: text/plain; charset=ISO-8859-1". However, this will
render the page in plaintext in stead of html.

I've read the rfc but I'm not entirely sure, as I understand it, if you
send content back, Content-Type and Content-Encoding are mandatory, no ?
Anyway, if not, I'd vote to not add the text/plain line and just send
the page on to the browser without a Content-Type field.

Could anybody confirm this for me ?

Thank you !

Peter.