It would be nice to check a JSP for unused taglibs (in the same way like Java code is checked for unused imports).
Expectation
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<html>
</html>
should report the issue but
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<html>
<c:import url ="menu.jsp" />
</html>
shouldn’t report the issue.