Yes! And everyone else should do so, too. I've created this
xhtml wizard that will create the code you need for both backwards and forwards compability.
(tip: check
IE and PHP)
Why is this relevant? Well, xhtml
must be sent as application/xhtml+xml in order to be
treated as xhtml by the client. If it's sent as text/html, the browser will parse it as html.
And we all know that <br /> is
invalid html?