Over the past few years we are seeing a gradual shift from websites using HTTP (Hypertext Transfer Protocol) to HTTPS (Hypertext Transfer Protocol Secure). HTTPS protocol enables secure connections and also brings potential positive SEO implications.
However, there's one major problem with the move: when a site using HTTPS refers traffic to a site that’s not using HTTPS, the HTTP Referrer header is lost - no referral data is sent along.
In other words, all traffic going from a trade with an HTTPS site to a trade with an HTTP site will be counted under
No referrer. The webmaster of the HTTPS site will have to take specific measures, so that traffic is tracked correctly on the HTTP site:
<meta name=“referrer” content=“unsafe-url”>in the
<head>section of your HTML. This will enable you to send the complete referrer information with the request.
referrerpolicy=“unsafe-url”to individual links. Here's an example:
<a target="_blank" href="https://public_html/your_te3_directory/out.php?s=100,100:2&u=http://www.duckduckgo.com/" referrerpolicy="unsafe-url">out -> unsafe</a>
You can read more about the meta referrer method here: https://moz.com/blog/meta-referrer-tag