I'm trying to include Facebook's OpenGraph new meta tags but when I add the required namespaces that would have worked in XHTML, HTML5 won't validate. <pre class="prettyprint"><code><!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:og="http://ogp.me/ns#" xmlns:fb="https://www.facebook.com/2008/fbml" dir="ltr" lang="en-US"> </code></pre> Where is the proper place to put these namespaces with HTML5?

There are no namespaces in HTML5 AFAIK: http://mortalpowers.com/news/no-namespaces-in-html5

How to include multiple XML namespaces in HTML5

Tags:

html

namespaces

xhtml

doctype

facebook-opengraph

I'm trying to include Facebook's OpenGraph new meta tags but when I add the required namespaces that would have worked in XHTML, HTML5 won't validate.

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:og="http://ogp.me/ns#" xmlns:fb="https://www.facebook.com/2008/fbml" dir="ltr" lang="en-US">

Where is the proper place to put these namespaces with HTML5?