What you need to know about Referrer Policy
Seeing some confusing referrer data in your analytics program? It might be the result of an issue with 'noreferrer.' Columnist Patrick Stox explains Referrer Policy, which lets webmasters define the value of the referrer header in outbound links.
If you’re running WordPress, did you notice a recent change in your analytics where more traffic is being attributed to direct traffic or a no-referral bucket? When WordPress updated to 4.7.4, the text editor TinyMCE also updated, and this is where the problem actually lies.
In November 2016, TinyMCE added a security update that added rel=”noopener noreferrer” on links with target=”_blank”. This has since been changed to remove the noreferrer part in TinyMCE, but I don’t believe WordPress has this update yet. With this, traffic that should count as referral traffic may be misattributed.