Denys Kondak

Viewport meta tag is used to adapt the site to various devices and to define its visible area for smartphone browsers. To activate it, you need to add a correctly adjusted tag in the Head section of the page code.

Webmasters need to analyze external links because a lot of them can lead to incorrect distribution of link weight and search engine sanctions. You should close external links from indexing to avoid such problems.

A self-signed SSL certificate does not provide sufficient protection to the data sent by a browser to the server. Unlike the certificates issued by reliable certification authorities, the identity of a self-signed SSL is verified by its owner.

Mixed content occurs when insecure elements are loaded over HTTP protocol to an SSL-protected page. An HTTPS page that contains any HTTP links is attackable which may influence SEO in a negative way.

HSTS technology should be implied only in case you secure correct https-protocol functioning on all the pages of your site. You can apply HTTP Strict Transport Security heading or add HSTS function in your hosting account to allow automatic transfer to safe connection.