Java EE (Java Enterprise Edition) General Discussion

I'm using the ${fn:substring()}

If I include it like this it works fine.
<%@taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>

but I much prefer to point the uri to something in my WEB-INF directory. This is for an intranet application and assures that an internet connection is not required for the application to run.

What would the correct tld be?