diff --git a/ChangeLog b/ChangeLog
index 4558b7b9a..23b0fac98 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2007-11-26  Badlop  <badlop@process-one.net>
 
+	* doc/guide.tex: Describe in mod_muc: nick register and service admin message (EJAB-400).
+
 	* src/mod_echo.erl: Example function that demonstrates how to receive XMPP packets using Erlang's message passing mechanism (EJAB-247).
 
 	* src/ejabberdctl.template: Removed bashisms (EJAB-399). Set environment variables instead of passing parameters when calling erl (EJAB-421). Write erl_crash.dump in the log/ directory, with unique filename (EJAB-433).
diff --git a/doc/guide.tex b/doc/guide.tex
index 6be0d0a63..b299bae15 100644
--- a/doc/guide.tex
+++ b/doc/guide.tex
@@ -2104,9 +2104,7 @@ Options:
 \ind{modules!\modmuc{}}\ind{protocols!XEP-0045: Multi-User Chat}\ind{conferencing}
 
 With this module enabled, your server will support Multi-User Chat
-(\xepref{0045}). End users will be able to join text conferences. Notice
-that this module is not (yet) clusterable.
-
+(\xepref{0045}). End users will be able to join text conferences.
 
 Some of the features of Multi-User Chat:
 \begin{itemize}
@@ -2117,6 +2115,23 @@ Some of the features of Multi-User Chat:
 \item Kicking and banning participants.
 \end{itemize}
 
+The MUC service allows any Jabber ID to register a nickname,
+so nobody else can use that nickname in any room in the MUC service.
+To register a nickname, open the Service Discovery in your 
+Jabber client and Register in the MUC service.
+
+The MUC service allows the service administrator to send a message
+to all existing chatrooms. 
+To do so, send the message to the Jabber ID of the MUC service.
+
+This module supports clustering and load
+balancing. One module can be started per cluster node. Rooms are
+distributed at creation time on all available MUC module
+instances. The multi-user chat module is clustered but the room
+themselves are not clustered nor fault-tolerant: if the node managing a
+set of rooms goes down, the rooms disappear and they will be recreated
+on an available node on first connection attempt.
+
 Options:
 \begin{description}
 \hostitem{conference}
@@ -2286,14 +2301,6 @@ defined, but some user restriction could be added as well:
 \end{verbatim}
 \end{itemize}
 
-The Multi-Users Chat module now supports clustering and load
-balancing. One module can be started per cluster node. Rooms are
-distributed at creation time on all available MUC module
-instances. The multi-user chat module is clustered but the room
-themselves are not clustered nor fault-tolerant: If the node managing a
-set of rooms goes down, the rooms disappear and they will be recreated
-on an available node on first connection attempt.
-
 \subsection{\modmuclog{}}
 \label{modmuclog}
 \ind{modules!\modmuclog{}}