<%@ Page language="C#" %> <%@ Register TagPrefix="mono" TagName="MonoSamplesHeader" src="~/controls/MonoSamplesHeader.ascx" %> <%-- we can even override the asp prefix with @ register --%> <%@ Register TagPrefix="Acme" namespace="System.Web.UI.WebControls" assembly="System.Web" %> <%@ Register TagPrefix="Acme" TagName="One" Src="registertest1.ascx" %> <%@ Register TagPrefix="Acme" TagName="Two" Src="registertest2.ascx" %> Register test