I posted this question: Google showing pages with ?page=2 urls and also read this post from Google: http://googlewebmastercentral.blogspot.in/2013/04/5-common-mistakes-with-relcanonical.html
I understand that node comments whether paginated or not are of low importance with respect to the node content itself. So all the paginated node pages reached by clicking links in the bottom just above "Post New Comment"( as in attachment) should have rel=canonical pointing to the main node page.
So these pages:
- example.com/node?page=2 and so on
should have "rel=canonical" in the head section of html page pointing to example.com/node.
Though as mentioned in the Google's blog, even "rel=prev" or "rel=next" may also be desirable in case of such urls.
So I need help how to add rel=canonical in those paginated node page. How can I do it?