Aaron D. Campbell

Expire Comment Links was inspired by <a href="http://yoast.com" rel="nofollow ugc">Joost de Valk</a> 
in an article he wrote called 
<a href="http://www.searchcowboys.com/columns/764" rel="nofollow ugc">Comment links: an experiment</a>. 
It all started when Matt Cutts talked about how Google changed how it handles no 
follow links in his article on 
<a href="http://www.mattcutts.com/blog/pagerank-sculpting/" rel="nofollow ugc">PageRank Sculpting</a>.
No one knows for sure yet if this will be beneficial or not, but for those that 
want to be on the cutting edge and try this experiment for themselves, this 
plugin automates everything.
Requires PHP5.
You may also be interested in <a href="http://wpinformer.com" rel="nofollow ugc">WordPress tips and tricks at WordPress Informer</a> or general <a href="http://webdevnews.net" rel="nofollow ugc">Web Developer News</a>

Expire Comment Links

Allows you to stop displaying links for old comments. PHP 5+ required.

Web Guy

<a href="https://github.com/webguyio/support" rel="nofollow ugc">💬 Ask Question</a> | <a href="mailto:webguywork@gmail.com" rel="nofollow ugc">📧 Email Me</a>
Adds the canonical link to your site (<a href="https://wikipedia.org/wiki/Canonical_link_element" rel="nofollow ugc">Learn More</a>).
Activate and then set your permalinks to “Post name” under Settings > Permalinks. That’s it.
Verify that it’s working correctly with the <a href="https://addons.mozilla.org/addon/canonical-link/" rel="nofollow ugc">Firefox add-on</a>.
Supports the ability to customize the canonical link for any specific page, post, or even custom post types (including WooCommerce Products and bbPress Topics).

Expire Comment Links vs Canonical Link