Google publishes document on more notable ranking systems

Google has published a new help document that talks about the more “notable” ranking systems Google has deployed over the years that are both currently in use and no longer in use in Google Search.The document is named a guide to Google Search ranking systems.Ranking systems in use. The document specifies that these are the ranking systems that are currently in use at Google Search. Google also provides a brief explanation of each ranking system. Note, some of these are multiple syst