Google updated their search quality raters guidelines PDF document a few days ago. Jennifer Slegg first noticed and documented most of the changes between this updated version and the March version, which focused on upsetting and offensive content.
The core change, according to Jennifer Slegg, is the new guidelines around non-English language pages. “This update seems primarily focused with international non-English results,” she said. “This is particularly where there are non-English languages being searched in, as well as cases where there might be both English and non-English mixed results from Google,” she added.
Another topic Google expanded on is conspiracy theories, i.e., how these quality raters should handle Google search results that return conspiracy theory content. Google also removed a section on the topic of pornographic ads being displayed on non-adult websites.
Jennifer Slegg did an outstanding job documenting the changes, so I recommend you review what she published on her site.
To be 100 percent clear, the quality raters do not have direct influence on how well or poorly an individual site ranks in Google. They merely give Google feedback on Google’s existing ranking algorithms and test algorithms. They cannot demote or hurt a site in the Google search results.
Source: Search Engine Land