diff --git a/doc/guide.html b/doc/guide.html
index 6e5127ea7..4a2bfd22b 100644
--- a/doc/guide.html
+++ b/doc/guide.html
@@ -2797,6 +2797,7 @@ service. If the <TT>host</TT> option is not specified, the Jabber ID will be the
 hostname of the virtual host with the prefix &#X2018;<TT>pubsub.</TT>&#X2019;. The keyword "@HOST@"
 is replaced at start time with the real virtual host name.
 
+If you use <TT>mod_pubsub_odbc</TT>, you can only use the prefix &#X2018;<TT>pubsub.</TT>&#X2019;.
 </DD><DT CLASS="dt-description"><B><TT>{access_createnode, AccessName}</TT></B></DT><DD CLASS="dd-description"> 
 This option restricts which users are allowed to create pubsub nodes using
 ACL and ACCESS.
diff --git a/doc/guide.tex b/doc/guide.tex
index 16d1ee2d7..d8f7b2a5d 100644
--- a/doc/guide.tex
+++ b/doc/guide.tex
@@ -3573,6 +3573,7 @@ and it requires \modcaps{}.
 Options:
 \begin{description}
 \hostitem{pubsub}
+  If you use \modpubsubodbc, you can only use the prefix `\jid{pubsub.}'.
 \titem{\{access\_createnode, AccessName\}} \ind{options!access\_createnode}
   This option restricts which users are allowed to create pubsub nodes using
   ACL and ACCESS.