XPages Extension Library namespace

The XPages Extension Library controls require an additional namespace which is automatically inserted in design mode. In source mode, insert the namespace manually.

A new XPage looks like this in source mode, defining one namespace for xp.
<?xml version="1.0" encoding="UTF-8"?>
<xp:view xmlns:xp="http://www.ibm.com/xsp/core">

</xp:view>
If you add a control from the XPages Extension Library in design mode, Domino(r)® Designer adds a namespace for xe. 
<xp:view xmlns:xp="http://www.ibm.com/xsp/core"
	xmlns:xe="http://www.ibm.com/xsp/coreex">
If you are working in source mode, make this adjustment manually.