JSF2 - Namespaces XHTML
Official namespaces for XHTML UI of a JSF2.2+ Java web application.
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://xmlns.jcp.org/jsf/facelets"
xmlns:h="http://xmlns.jcp.org/jsf/html"
xmlns:f="http://xmlns.jcp.org/jsf/core"
xmlns:c="http://xmlns.jcp.org/jsp/jstl/core"
xmlns:p="http://xmlns.jcp.org/jsf/passthrough"
xmlns:fn="http://xmlns.jcp.org/jsp/jstl/functions"
xmlns:cc="http://xmlns.jcp.org/jsf/composite"
xmlns:jsf="http://xmlns.jcp.org/jsf">
</html>
Documentation: https://docs.oracle.com/javaee/7/javaserver-faces-2-2/vdldocs-facelets/toc.htm
