How ASP.NET MVC routing module works

http://www.simple-talk.com/dotnet/.net-framework/asp.net-mvc-routing-extensibility/

routes.MapRoute("BlogArchive",

    "{year}/{month}/{day}",

    new { controller = "Blog", action = "List", month = "1", day = "1" },

    new { year = @"\d{2}|\d{4}", month = @"\d{1,2}", day = @"\d{1,2}" }

    );