In this example, a blog post can be associated with multiple categories (MVC3, Razor, etc.). To allow editors to select which categories apply to a blog, the view loops through all available categories and renders a checkbox for each one.
When working with ASP.NET MVC routing, the order in which you register routes inside Global.asax.cs is critical. Routes are evaluated from top to bottom, and the first matching route wins. If a more general route appears before a more specific one, it can intercept the request and prevent the intended controller from being reached.