title: confused about xhtml5: no more `<?xml?>` and now mandatory `meta`?
body: <p>I've been a longtime user of <code>XHTML 1.0 Strict</code>, and I'm now trying to switch to XHTML5 in my new projects.</p>
  
  <p>I'm confused that <code>&lt;?xml version='1.0' encoding='utf-8'?&gt;</code> is no longer considered valid, for HTML5, by <a href="http://validator.w3.org/" rel="noreferrer">http://validator.w3.org/</a>.  Why is that?  Isn't that what all xml documents are supposed to start with?</p>
  
  <p>And when I remove the standard <code>&lt;?xml</code>&hellip;, my document still doesn't validate:  now it's missing the encoding.  I don't like those <code>meta</code> tags, but are they now effectively mandatory, to specify the encoding, in order to be valid (X)HTML5?</p>