Internet Explorer 6 Navigate Restrictions

I was recently looking through the msdn documentation and encountered
this quote in the documentation for the IWebBrowser2.Navigate and
IWebBrowser2.Navigate2 method:

"In Internet Explorer 6 or later, you can navigate through code only
within the same domain as the application hosting the WebBrowser
control. Otherwise, this method is disabled."

Could someone explain to me when this restriction applies and how it
works. Testing on my desktop (with IE 6 installed, but not a member of
a domain) I am able to navigate the webbrowser to whatever web url I
require. Does this only apply if the webbrowser control is hosted in a
web page or run from a web page (such as in .NET 2.0)?

Thank you

.