URL Canonicalization I believe is where you can force (for example) the non WWW version of your URL to redirect to the WWW version of your URL. Or viceversa. In fact, here it is viceversa and www.xenforo.com redirects to xenforo.com.
I believe XenForo does this automagically via this code:
<link rel="canonical" href="http://xenforo.com/community/" />
And on my site, ValveTime.net:
<link rel="canonical" href="http://www.valvetime.net/forum/" />
However, for us it doesn't seem to be working.
What might I be missing?
I've even added some recommended rewrites into the .htaccess and it still doesn't work.
Effectively, http://www.valvetime.net is different to valvetime.net.