diff --git a/xep.ent b/xep.ent
index 8bd0d06e..d015f681 100644
--- a/xep.ent
+++ b/xep.ent
@@ -303,6 +303,7 @@
 <!ENTITY rfc2451 "<span class='ref'>RFC 2451</span> <note>RFC 2451: The ESP CBC-Mode Cipher Algorithms &lt;<link url='http://tools.ietf.org/html/rfc2451'>http://tools.ietf.org/html/rfc2451</link>&gt;.</note>" >
 <!ENTITY rfc2510 "<span class='ref'>RFC 2510</span> <note>RFC 2510: Internet X.509 Public Key Infrastructure Certificate Management Protocols &lt;<link url='http://tools.ietf.org/html/rfc2510'>http://tools.ietf.org/html/rfc2510</link>&gt;.</note>" >
 <!ENTITY rfc2518 "<span class='ref'>RFC 2518</span> <note>RFC 2518: HTTP Extensions for Distributed Authoring -- WEBDAV &lt;<link url='http://tools.ietf.org/html/rfc2518'>http://tools.ietf.org/html/rfc2518</link>&gt;.</note>" >
+<!ENTITY rfc2518bis "<span class='ref'>rfc2518bis</span> <note>RFC 2518: HTTP Extensions for Distributed Authoring -- WebDAV &lt;<link url='http://www.ietf.org/internet-drafts/draft-ietf-webdav-rfc2518bis-17.txt'>http://www.ietf.org/internet-drafts/draft-ietf-webdav-rfc2518bis-17.txt</link>&gt;.</note>" >
 <!ENTITY rfc2606 "<span class='ref'>RFC 2606</span> <note>RFC 2606: Reserved Top Level DNS Names &lt;<link url='http://tools.ietf.org/html/rfc2606'>http://tools.ietf.org/html/rfc2606</link>&gt;.</note>" >
 <!ENTITY rfc2616 "<span class='ref'>RFC 2616</span> <note>RFC 2616: Hypertext Transport Protocol -- HTTP/1.1 &lt;<link url='http://tools.ietf.org/html/rfc2616'>http://tools.ietf.org/html/rfc2616</link>&gt;.</note>" >
 <!ENTITY rfc2617 "<span class='ref'>RFC 2617</span> <note>RFC 2617: HTTP Authentication: Basic and Digest Access Authentication &lt;<link url='http://tools.ietf.org/html/rfc2617'>http://tools.ietf.org/html/rfc2617</link>&gt;.</note>" >