Notes from the Google Webmaster Hangout on the 6th of October, 2017.
Appearance in Top Stories Is Determined Algorithmically
The appearance of pages in Top Stories is determined algorithmically. If pages are indexed normally but not appearing in Top Pages, it’s likely to be due to quality factors, such as content above the fold and interstitials.
Add Unique Content So International Duplicate Pages Can Be Indexed Separately
Including some unique content on international duplicate pages, such as local addresses and currencies, will prevent them being folded together and allow them to be indexed separately.
Crawl Errors May Take Months to Clear
Broken URLs which are being shown as Crawl Errors may not be crawled frequently and may take many months to be re-crawled before they are dropped. Unless they are important pages which should be indexed, they can be ignored.
Only Change Protocol During an HTTPS Migration
An HTTPS migration can be processed much faster providing only the HTTPS protocol changes, and the domain, URL path and parameters don’t change.
URL Removal Tool Works for Any Domain
If a page has been removed from a site with a 404, you can use the URL removal tool to remove it from Google’s index, including other domains you don’t directly control.
A Noindex Reduces Crawl Rate
A page with a noindex tag will be crawled less frequently.
Content on Canonicalised Paginated Pages Will Be Lost
Unique content and links on canonicalised paginated pages will be lost if Google accepts the canonical directive.
Update Internal Links to Canonical URLs
Update internal links to canonical URLs to give Google a clean signal about which URL to index. If the canonical is accepted, any links to canonicalised URLs will be associated with the canonical URL.
Moving to a CDN May Temporarily Reduce Crawl Rate
If you move your site to a CDN, Google sees it as a new hosting setup and may temporarily reduce the crawl rate.
Use 301s to Migrate a Subdomain to a Subfolder
You can’t use the Search Console site migration tool to move a subdomain to a subfolder, but 301 redirections are fine.