2goforward on "How to remove/hide rss tags in xml from customized rss feed"

I created a customized rss feed that does everything the vendor requires, except one thing. The vendor does not want any rss tags in the resulting xml. Without those rss tags, Firefox does not know what to do when I enter the feed URL and asks whether it should open another application or save the file. How do I remove/hide the rss tags from an rss feed? It should not be visible when I choose View Page Source. test1.smartleasingplus.com/feed/syndication/?post_type=estate_property

header('Content-Type: ' . feed_content_type('rss') . '; charset=' . get_option('blog_charset'), true);
$more = 1;

echo '<?xml version="1.0" encoding="'.get_option('blog_charset').'"?'.'>'; ?>
<rss version="0.92"></rss>