<p>Today it is a method to prevent child searching the web from receiving adult content. Although focused on keeping childern safe, the method can be used on any account.</p>
<li>Parents need to turn on <ahref="http://windows.microsoft.com/en-us/windows/set-up-family-safety#set-up-family-safety=windows-8">Parental Controls in Windows</a> for their children's account.</li>
<li>IE recognize that Parental Controls is turned on and indicate to Bing that the user prefers to receive safe results.</li>
<li>Bing respects the preference and sends back only results classified as non-adult.</li>
The safe search preference is communicated via the HTTP header <code>"prefer:safe"</code>.
For more information about the header, you can refer to the <ahref="https://tools.ietf.org/html/draft-nottingham-safe-hint-05">Internet draft specification</a> submitted to the IETF (Internet Engineering Task Force).
Ultimately, it's up to the website or service owners to honor the safe preference when the browser communicates it to them on the user's behalf, and respond accordingly.
We're hoping that more browsers, websites, and services will embrace the standard so that we collectively help build a safer web for our children.