Why when add <?xml version=“1.0” encoding=“utf-8”?> to web page don´t work on hosting?

Question

I am developing a simple webpage at hostgator.com. I have the standard headers, but when I add the following line:

Answer 1

<?php
echo '<?xml version="1.0" encoding="utf-8"?>';
?>

Answer 2

My best guess is that:

• The document is being processed as PHP
• Short Tags are turned on

… so the server is trying to process the XML declaration as PHP code. Normally I'd expect an error message, but perhaps there is a PHP setting in play that suppresses errors to the client to avoid leaking data that could be potentially useful to someone trying a security exploit.

Just remove it.

• UTF-8 is the default
• version 1.0 is the default
• It is optional in the spec
• Given a text/html content-type, an XML prolog will trigger IE6's quirks mode

The latter is undesirable. The former all mean it makes no difference.