http://blogs.windows.com/msedgedev/2015/06/09/http-strict-transport-security-comes-to-internet-explorer-11-on-windows-8-1-and-windows-7/ [blogs.windows.com]

HTTP Strict Transport Security comes to Internet Explorer 11 on Windows 8.1 and Windows 7

The HTTP Strict Transport Security (HSTS) policy protects against variants of man-in-the-middle attacks that can strip TLS out of communications with a server, leaving the user vulnerable.

With today’s monthly security updates (KB 3058515), we’re bringing the protections offered by HSTS to Internet Explorer 11 on Windows 8.1 and Windows 7. HSTS is also available in both Internet Explorer 11 and Microsoft Edge on Windows 10.