The referrer header has always been optional, and nothing governs the specifics of its contents beyond the host and page. Google never had to provide anything b

The referrer header has always been optional, and nothing governs the specifics of its contents beyond the host and page. Google never had to provide anything beyond "Google search results page" as the referrer, and probably never should have. After all, the search page is a form, and form submissions generally use POST rather than GET. Both are valid, but if Google used POST then the search terms would never have been part of the url for the results page, and never would have been passed on in the referrer urls.