Web.xml version
With jstl config below:
<%@taglib prefix="c" uri="http://java.sun.com/jstl/core" %>
Only valid for config web.xml below in v2.3:
<web-app id="WebApp_ID" version="2.3" 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_3.xsd">
If jstl config
<%@taglib prefix="c" uri="http://java.sun.com/jstl/core" %>
using web.xml v2.4:
<web-app id="WebApp_ID" version="2.4" 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">
It will throw error, suppose for EL(Expression Language):
According to TLD or attribute directive in tag file, attribute value does not accept any expressions