When using Wordpress comments you can easily reply to a comment directly on the page by clicking on a reply link which will be positioned next to the comment.
after - HTML to add after the comment reply
As you can see from the above options there are lots of things you can do to customise the reply link that is displayed in the comments section. But there is an SEO problem is this reply link. ## SEO Problem With Reply Link
This reply link will include the comment ID in the URL and will send you back to the page with the comment form in place to make your reply to the comment. The problem is that search engines can follow this link on your page and will index the page the links goes to. This page is the same as the current page but will have additional query string options to take to back to the comment form. These URLs are then indexed in the search engines creating duplicate context in the search engine index. A good way to solve this problem is to add a rel="nofollow" to all your comment reply links, which tells search engines not to follow this link. Below is a Wordpress snippet to add to your functions.php file to add a rel="nofollow" attribute to your comment reply links.
add_filter( 'comment_reply_link', 'add_nofollow_to_reply_link' );
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