Site authors must ensure that a hyperlink to the common group privacy policy is placed on the default page of each domain listed on their proposed set; such that an automated technical check can be used to verify its presence.

I'm having hard time imagining how this could be automated without creating special html markup or enforcing special usage of existing markup, given that websites could be on different languages, with different links, etc. Also it isn't clear who exactly is going to parse all the websites, browsers or third-party entities. But in any case, it sounds like such a thing would require its own specification.

It might be better if common privacy policy would be provided in .well-known endpoints and browsers would display it consistently in their UI for FPS websites.