SF_10.1, SF_10.2 - https://docs.sitefinity.com/for-developers-override-the-page-strategies

CustomFrontendPageKeyStrategy_Global.asax.cs

using Telerik.Microsoft.Practices.Unity;
using Telerik.Sitefinity.Abstractions;
using Telerik.Sitefinity.Data;
using Telerik.Sitefinity.Web.Compilation;

namespace SitefinityWebApp
{
    public class Global : System.Web.HttpApplication
    {

        private void BootstrapperInitialized(object sender, ExecutedEventArgs e)
        {
            if (e.CommandName == "Bootstrapped")
            {
                ObjectFactory.Container.RegisterType<IPageKeyStrategy, CustomFrontendPageKeyStrategy>("Frontend");
            }
        }
    }
}