If the connection to your page is not encrypted, all communication between your site and its users can be intercepted and manipulated.
max-age=63072000; includeSubdomains; HTTP Strict Transport Security (HSTS) is a web security policy mechanism that is easy to integrate.
# Activate HTTP Strict Transport Security (HSTS) # Required: "max-age"
# Optional: "includeSubDomains"
Header set Strict-Transport-Security "max-age=31556926; includeSubDomains"
Here is an example of an .htaccess file which will set the Header Scanner to green. (.htaccess example)