Taglibs

Lectura http://jakarta.apache.org/taglibs/tutorial.html#tag_handler .
El web.xml no reconoce el elemento , el web app es:
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd