I think
cwc
is
TagPrefix
For registering Telerik.Web.UI you can use something like this:
<![CDATA[<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>]]>
and are helpful to access telerik controls using tagprefix as
<telerik:RadGrid ID="gridview" AllowMultiRowSelection="True" runat="server"
AllowFilteringByColumn="true" GridLines="None" CellSpacing="1" CssClass="RadGrid_WebBlue"
Width="100%" Skin="WebBlue" AllowPaging="true" PageSize="50">