Vladimir Kolesnikov

Adds the referrering link from which a commenting user came from to comment notifications and Comments screen in the Admin panel of your site.
This is an extended version of Donncha’s <a href="https://wordpress.org/extend/plugins/comment-referrers/" rel="ugc">Comment Referrers</a> plugin
ICS Comment Referrer:
<ul>
<li>uses both server (HTTP Referer header) and client (works if JavaScript enabled) referrer identification;</li>
<li>cryptographically protects the server-generated referrer field;</li>
<li>adds referring links to comment notifications;</li>
<li>shows referring links in Admin Panel » Comments.</li>
</ul>
<h3>Contributors</h3>
<ul>
<li><a href="http://blog.sjinks.pro/" rel="nofollow ugc">Vladimir Kolesnikov</a></li>
<li><a href="https://launchpad.net/~rahermosillac" rel="nofollow ugc">Ricardo A. Hermosilla Carrillo</a></li>
<li><a href="https://launchpad.net/~pierre-slamich" rel="nofollow ugc">Pierre Slamich</a></li>
<li><a href="https://launchpad.net/~sunder67" rel="nofollow ugc">zeugma</a></li>
<li><a href="https://launchpad.net/~elkan76" rel="nofollow ugc">Mauricio Peñaloza S.</a></li>
</ul>
<h3>Bug Reports</h3>
Please use <a href="https://bugs.launchpad.net/wp-plugin-comment-referrer/+filebug" rel="nofollow ugc">Launchpad</a> to report any bugs.

ICS Comment Referrer

Adds the referrering link from which a commenting user came from to comment notifications and Comments screen in the Admin panel of your site.

Medium Interactive

Tired of spam form submissions from suspicious referral sources? Want to block or redirect traffic from specific ad networks that send low-quality leads? Managing traffic quality shouldn’t require a developer. We made it easy!
Smart Traffic Source Filter gives WordPress site owners complete control over user experience based on traffic origin. By analyzing the HTTP referrer (both server-side via PHP and client-side via JavaScript when headers are missing), this plugin makes it easy to detect where visitors come from and apply different behavior—whether you need to filter spam, protect forms, redirect unwanted traffic, or optimize conversions for high-quality sources.
You can define specific referrer domains or patterns, and when a visitor matches those conditions, the plugin can:
<ul>
<li>Display a small notification (server-side) showing the detected referrer host or path.</li>
<li>Hide or reveal specific elements on your site using CSS selectors.</li>
<li>Redirect visitors from certain sources to a different URL.</li>
</ul>
This gives marketers, advertisers, and site owners fine control over how different audiences see the site.
Example use cases:
<ul>
<li>Hide contact forms when users arrive through syndicated search traffic to prevent spam or low-quality leads.</li>
<li>Hide pricing details when a user comes from social media to encourage engagement before pricing exposure.</li>
<li>Redirect visitors from affiliate networks to a dedicated landing page.</li>
<li>Show a simple banner confirming that the user arrived via a partner campaign.</li>
</ul>
The plugin sets a tracking cookie (<code>mdi_syndicated_ref</code>) to remember the detected source for the configured number of days, ensuring consistent visibility rules on repeat visits.
MDI HTTP Referer Block helps you tailor on-site experiences dynamically based on real visitor origin — simple, server-side controlled, and privacy-respecting.
For a full guide on blocking syndicated search traffic (e.g., Google Ads Performance Max), see: 
https://mediuminteractive.com/how-to-block-syndicated-search-traffic-from-performance-max-campaigns-in-google-ads/

Smart Traffic Source Filter for WordPress

Hide elements or redirect users based on referrer domains. Useful for blocking partners, scrapers, or altering content per source.

ICS Comment Referrer vs Smart Traffic Source Filter for WordPress