il mio è con tutti e due:

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="content-type" content="text/html; charset=utf-8" /><title>....

ma se ometto <?xml version="1.0" encoding="UTF-8"?> mi restituisce dei caratteri strani anche se ho <meta http-equiv="content-type" content="text/html; charset=utf-8" />