These special URLs are not present in MSIE although there will be some internal resources in that browser which may provide customization opportunities in a similar way. Indeed, Microsoft provide an administrator kit which you can use to customize the browser installation.
You may also be able to obtain admin tools from Netscape and Microsoft to carry out legitimate customizations on the browsers before deploying them throughout your organization.
Here are some examples:
|nethelp:netscape/home:start_here||Front page of the help system|
This appears to have changed somewhat in Netscape 6.0, which is likely to provide a whole range of new possibilities. Once the browser is fully debugged and working we can spend many happy hours inspecting it to discover them.
This is not present in MSIE at all. It displays help using a completely different mechanism altogether.