diff --git a/xep.ent b/xep.ent
index 53afdf7c..c093dbbd 100644
--- a/xep.ent
+++ b/xep.ent
@@ -555,6 +555,7 @@ THE SOFTWARE.
 <!ENTITY rfc4566 "<span class='ref'><link url='http://tools.ietf.org/html/rfc4566'>RFC 4566</link></span> <note>RFC 4566: SDP: Session Description Protocol &lt;<link url='http://tools.ietf.org/html/rfc4566'>http://tools.ietf.org/html/rfc4566</link>&gt;.</note>" >
 <!ENTITY rfc4568 "<span class='ref'><link url='http://tools.ietf.org/html/rfc4568'>RFC 4568</link></span> <note>RFC 4568: Session Description Protocol (SDP) Security Descriptions for Media Streams &lt;<link url='http://tools.ietf.org/html/rfc4568'>http://tools.ietf.org/html/rfc4568</link>&gt;.</note>" >
 <!ENTITY rfc4571 "<span class='ref'><link url='http://tools.ietf.org/html/rfc4571'>RFC 4571</link></span> <note>RFC 4571: Framing Real-time Transport Protocol (RTP) and RTP Control Protocol (RTCP) Packets over Connection-Oriented Transport &lt;<link url='http://tools.ietf.org/html/rfc4571'>http://tools.ietf.org/html/rfc4571</link>&gt;.</note>" >
+<!ENTITY rfc4575 "<span class='ref'><link url='http://tools.ietf.org/html/rfc4575'>RFC 4575</link></span> <note>RFC 4575: A Session Initiation Protocol (SIP) Event Package for Conference State &lt;<link url='http://tools.ietf.org/html/rfc4575'>http://tools.ietf.org/html/rfc4575</link>&gt;.</note>" >
 <!ENTITY rfc4585 "<span class='ref'><link url='http://tools.ietf.org/html/rfc4585'>RFC 4585</link></span> <note>RFC 4585: Extended RTP Profile for Real-time Transport Control Protocol (RTCP)-Based Feedback (RTP/AVPF) &lt;<link url='http://tools.ietf.org/html/rfc4585'>http://tools.ietf.org/html/rfc4585</link>&gt;.</note>" >
 <!ENTITY rfc4622 "<span class='ref'><link url='http://tools.ietf.org/html/rfc4622'>RFC 4622</link></span> <note>RFC 4622: Internationalized Resource Identifiers (IRIs) and Uniform Resource Identifiers (URIs) for the Extensible Messaging and Presence Protocol (XMPP) &lt;<link url='http://tools.ietf.org/html/rfc4622'>http://tools.ietf.org/html/rfc4622</link>&gt;.</note>" >
 <!ENTITY rfc4627 "<span class='ref'><link url='http://tools.ietf.org/html/rfc4627'>RFC 4627</link></span> <note>RFC 4627: The application/json Media Type for JavaScript Object Notation (JSON) &lt;<link url='http://tools.ietf.org/html/rfc4627'>http://tools.ietf.org/html/rfc4627</link>&gt;.</note>" >