What is MapRoute namespaces parameter for?

ASP.NET MVC's MapRoute method has a parameter named namespaces. From looking in the code, I see that this parameter is saved in the Route objec开发者_如何转开发t in DataTokens["Namespaces"].

It seems to me that it has some meaning... anyone knows what is it for?

In MVC4 'namespaces' parameters is no longer a secret, it optionally provides namespaces to search for controllers. It can be used with Areas, for example.

Documentation: http://msdn.microsoft.com/en-us/library/dd492682(v=vs.108).aspx

I think this question should be deleted as outdated.