diff --git a/en/tutorials/docproj-primer/sgml-markup/chapter.sgml b/en/tutorials/docproj-primer/sgml-markup/chapter.sgml
index e749463375..6ab0086a0b 100644
--- a/en/tutorials/docproj-primer/sgml-markup/chapter.sgml
+++ b/en/tutorials/docproj-primer/sgml-markup/chapter.sgml
@@ -732,7 +732,7 @@ PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"</programlisting>
 	  is;</para>
 
 	<programlisting>
-PUBLIC "-//FreeBSD//DTD DocBook V3.0-Based Extension//EN"</programlisting>
+PUBLIC "-//FreeBSD//DTD DocBook V3.1-Based Extension//EN"</programlisting>
     </sect2>
       
     <sect2>
@@ -1516,7 +1516,7 @@ This is the file called 'foo2'</screen>
 	<para>Therefore, the introduction to your documentation will probably
 	  look like this;</para>
 
-	<programlisting>&lt;!DOCTYPE book PUBLIC "-//FreeBSD//DTD DocBook V3.0-Based Extension//EN" [
+	<programlisting>&lt;!DOCTYPE book PUBLIC "-//FreeBSD//DTD DocBook V3.1-Based Extension//EN" [
 
 &lt;!ENTITY % man PUBLIC "-//FreeBSD//ENTITIES DocBook Manual Page Entities//EN"&gt;
 %man;
diff --git a/en_US.ISO8859-1/books/fdp-primer/sgml-markup/chapter.sgml b/en_US.ISO8859-1/books/fdp-primer/sgml-markup/chapter.sgml
index e749463375..6ab0086a0b 100644
--- a/en_US.ISO8859-1/books/fdp-primer/sgml-markup/chapter.sgml
+++ b/en_US.ISO8859-1/books/fdp-primer/sgml-markup/chapter.sgml
@@ -732,7 +732,7 @@ PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"</programlisting>
 	  is;</para>
 
 	<programlisting>
-PUBLIC "-//FreeBSD//DTD DocBook V3.0-Based Extension//EN"</programlisting>
+PUBLIC "-//FreeBSD//DTD DocBook V3.1-Based Extension//EN"</programlisting>
     </sect2>
       
     <sect2>
@@ -1516,7 +1516,7 @@ This is the file called 'foo2'</screen>
 	<para>Therefore, the introduction to your documentation will probably
 	  look like this;</para>
 
-	<programlisting>&lt;!DOCTYPE book PUBLIC "-//FreeBSD//DTD DocBook V3.0-Based Extension//EN" [
+	<programlisting>&lt;!DOCTYPE book PUBLIC "-//FreeBSD//DTD DocBook V3.1-Based Extension//EN" [
 
 &lt;!ENTITY % man PUBLIC "-//FreeBSD//ENTITIES DocBook Manual Page Entities//EN"&gt;
 %man;
diff --git a/en_US.ISO_8859-1/books/fdp-primer/sgml-markup/chapter.sgml b/en_US.ISO_8859-1/books/fdp-primer/sgml-markup/chapter.sgml
index e749463375..6ab0086a0b 100644
--- a/en_US.ISO_8859-1/books/fdp-primer/sgml-markup/chapter.sgml
+++ b/en_US.ISO_8859-1/books/fdp-primer/sgml-markup/chapter.sgml
@@ -732,7 +732,7 @@ PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"</programlisting>
 	  is;</para>
 
 	<programlisting>
-PUBLIC "-//FreeBSD//DTD DocBook V3.0-Based Extension//EN"</programlisting>
+PUBLIC "-//FreeBSD//DTD DocBook V3.1-Based Extension//EN"</programlisting>
     </sect2>
       
     <sect2>
@@ -1516,7 +1516,7 @@ This is the file called 'foo2'</screen>
 	<para>Therefore, the introduction to your documentation will probably
 	  look like this;</para>
 
-	<programlisting>&lt;!DOCTYPE book PUBLIC "-//FreeBSD//DTD DocBook V3.0-Based Extension//EN" [
+	<programlisting>&lt;!DOCTYPE book PUBLIC "-//FreeBSD//DTD DocBook V3.1-Based Extension//EN" [
 
 &lt;!ENTITY % man PUBLIC "-//FreeBSD//ENTITIES DocBook Manual Page Entities//EN"&gt;
 %man;