Notes from the Google Webmaster Hangout on the 4th of October 2019.
Google Uses the Viewport Tag to Understand the Mobile-friendliness of a Page
The viewport tag is used for scaling a page for devices, and Google will use this tag to understand whether the page is mobile-friendly or not. Google won't automatically categorise a page as a mobile version if it has a viewport tag.
Google Advises Against Using Separate Mobile URLs
Having separate URLs for the mobile and desktop version of a site adds more complexity for website owners to manage, so Google recommends switching to a responsive setup.
It's Fine to Re-publish Content From Discontinued Sites on Another Relevant Site
If you have permission to re-publish content from a site that has been taken down, then it is fine to do so.
Affiliate Links Don't Impact Site Quality But Should Have Rel=sponsored Attribute
Having affiliate links can be a genuine way to monetise a website, and this doesn't impact the perceived quality of a site for Google. It's recommended that you add rel=sponsored to these types of links, which means that they will be nofollowed.
There Are No Issues With Having More Than One Author For a Post
Google has no issues with having more than one author attributed on a post.
New Snippet Robots Meta Tags Aren't Essential
You don't have to implement the new snippet meta tags to appear in search results and in rich results. They are optional, and can be used to set things like maximum character counts, the size of image previews, and the length of video previews. John recommends using these tags only if you want to change the way your snippets are currently shown in search.
If Testing Tools Are Picking Up Structured Data Google Should be Able to As Well
Google Needs to Access JS Files & Server End Points Used For AJAX Requests
Confirm PageSpeed Insights & Structured Data Testing Tool IP Addresses with Test Page
PageSpeed Insights and the Structured Data Testing Tool use different IP addresses than Googlebot. There isn't a list of IP addresses that they currently use, so check this using a test page and analyse the requests coming from these tools.
External Links Shown in GSC Can Contain Disavowed or Nofollowed Links
The external links shown in Google Search Console are a sample of all the links found by Google, so not all of them will be displayed in the tool. The sample data may include links that have been disavowed or nofollowed.
Links Don't Depreciate in Value Over Time, But Pages They're Found on Can
The signals that a link has won't depreciate in value over time. However, the pages that the links are found on and link to externally may become less important over time as they are hidden deeper within a site's architecture, especially if it is a site that is changed and updated often.
Be the First to Know About the Latest Insights From Google