Google has updated documentation explaining to the webmasters how to use the canonical URL. The changes were first discovered and fixed by the specialist in the industry Menashe Avramov.
The complete list of changes could be found on the Google+ at the user page.
Changes have been made in the Russian version of the Google Help already. It’s mostly due to the massive transfer sites on the secure HTTPS protocol and the desire of Google to index such resources quickly and accurately.
In January this year, a Google spokesman John Mueller said that the canonical URL to HTTPS pages should not indicate their HTTP-version.
For the first time that Google in the test mode will start to consider the use of HTTPS on the site as a signal for ranking became known in summer 2014.