Google has published a new guide to its search ranking systems, which it says is now a centralised page to help it communicate how its systems work, along with updates.

[developers.google.com...]

This appears to be in addition to the other pages.
List of Google Search ranking updates [developers.google.com]
Google Search's core updates and your website [developers.google.com]
Google Search's helpful content update and your website [developers.google.com]
Google Search's product reviews update and your website [developers.google.com]
Google Search spam updates and your site [developers.google.com]