webapps/ROOT/index.jsp is shadowed by servlet: <servlet> <servlet-name>org.apache.jsp.index_jsp</servlet-name> <servlet-class>org.apache.jsp.index_jsp</servlet-class> </servlet> <servlet-mapping> <servlet-name>org.apache.jsp.index_jsp</servlet-name> <url-pattern>/index.jsp</url-pattern> </servlet-mapping> This means that you can modify index.jsp but you won't see any change, because the path "/index.jsp" is redirected in web.xml. Me and a co-worker just lost half an hour to this thing, trying to figure out where our redirection went. If you're going to keep "/index.jsp" in a servlet, fine, rename the index.jsp file to index.jsp.example. But having it shadowed is incredibly user-hostile.
Having a comment on the page is not sufficient, because typically the developer will not even look at the default page; it will be replaced by a new index.jsp. If the file was only named "index.jsp.example", it wouldn't be a hazard. As it is, this is just obnoxious.