Notes from the Google Webmaster Hangouts on the 4th of November, 2016.
Similar Country Pages May Be Treated as Duplicates
Country specific pages which are very near duplicates may still be folded together, even if the pages include hreflang tags. If you include more unique content for each version, it is less likely to happen.
Use Linking and Noindex to Control Sitelinks
Google has removed the Remove Sitelink option in Search Console, as they had demoted the power of it, so you cannot remove them directly in any way. But you can change your internal linking, a clean navigation in particular, to promote pages, and use a noindex to remove any pages from Google’s index completely.
Google May Choose a Redirect URL Instead of the Target
Separate Mobile Pages May Appear for Site: Queries
Sometimes you may see your mobile URLs appear for site: queries, but they might not be indexed. Check the cached version of the pages to see what content has been indexed for those URLs.
Migrate to HTTPS If You’re Moving Domains
If you are going to migrate your domain, it’s best to migrate to HTTPS at the same time. However changing URL structure and moving to a new domain is much harder for Google to pick up.