diff --git a/doc/Clusters_from_Scratch/en-US/Preface.xml b/doc/Clusters_from_Scratch/en-US/Preface.xml
index edea6784e1..0e32108da6 100644
--- a/doc/Clusters_from_Scratch/en-US/Preface.xml
+++ b/doc/Clusters_from_Scratch/en-US/Preface.xml
@@ -1,13 +1,13 @@
 <?xml version='1.0' encoding='utf-8' ?>
 <!DOCTYPE preface PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
 <!ENTITY % BOOK_ENTITIES SYSTEM "Clusters_from_Scratch.ent">
 %BOOK_ENTITIES;
 ]>
-<preface id="pref-Clusters_from_Scratch-Preface">
+<preface>
 	<title>Preface</title>
 	<xi:include href="Common_Content/Conventions.xml" xmlns:xi="http://www.w3.org/2001/XInclude" />
 	<xi:include href="Feedback.xml" xmlns:xi="http://www.w3.org/2001/XInclude"><xi:fallback xmlns:xi="http://www.w3.org/2001/XInclude"><xi:include href="Common_Content/Feedback.xml" xmlns:xi="http://www.w3.org/2001/XInclude" />
 	</xi:fallback>
 	</xi:include>
 </preface>