Yesterday I spotted that Google updated its Search Quality raters guidelines (PDF download). George Nguyen from Search Engine Land dug into the changes, you can read the details over there. In short, Google added a page to the guidelines, bringing it up to 168 pages. Google added an introduction page and not much else. George said the changes “emphasized diversity, impartiality and pertained to language referring to users.”

You can compare the two documents yourself, from when Google updated them on September 5, 2019:

September 5th PDF download link
December 5th PDF download link

Again, you can read about what changed at Search Engine Land instead of doing a diff yourself.

Forum discussion at Twitter.