diff --git a/reference/libxml/constants.xml b/reference/libxml/constants.xml
index 06f0075704..7ebec0894a 100755
--- a/reference/libxml/constants.xml
+++ b/reference/libxml/constants.xml
@@ -1,9 +1,26 @@
 <?xml version='1.0' encoding='iso-8859-1'?>
-<!-- $Revision: 1.3 $ -->
+<!-- $Revision: 1.4 $ -->
 <section id="libxml.constants">
  &reftitle.constants;
  &extension.constants;
  <variablelist>
+  <varlistentry>
+   <term>
+    <constant>LIBXML_COMPACT</constant>
+     (<type>integer</type>)
+   </term>
+   <listitem>
+    <simpara>
+     Activate small nodes allocation optimization. This may speed up your
+     application without needing to change the code.
+    </simpara>
+    <note>
+     <para>
+      Only available in Libxml &gt;= 2.6.21
+     </para>
+    </note>
+   </listitem>
+  </varlistentry>
   <varlistentry>
    <term>
     <constant>LIBXML_DTDATTR</constant>
@@ -37,50 +54,6 @@
     </simpara>
    </listitem>
   </varlistentry>
-  <varlistentry>
-   <term>
-    <constant>LIBXML_ERR_ERROR</constant>
-     (<type>integer</type>)
-   </term>
-   <listitem>
-    <simpara>
-     A recoverable error
-    </simpara>
-   </listitem>
-  </varlistentry>
-  <varlistentry>
-   <term>
-    <constant>LIBXML_ERR_FATAL</constant>
-     (<type>integer</type>)
-   </term>
-   <listitem>
-    <simpara>
-     A fatal error
-    </simpara>
-   </listitem>
-  </varlistentry>
-  <varlistentry>
-   <term>
-    <constant>LIBXML_ERR_NONE</constant>
-     (<type>integer</type>)
-   </term>
-   <listitem>
-    <simpara>
-     No errors
-    </simpara>
-   </listitem>
-  </varlistentry>
-  <varlistentry>
-   <term>
-    <constant>LIBXML_ERR_WARNING</constant>
-     (<type>integer</type>)
-   </term>
-   <listitem>
-    <simpara>
-     A simple warning
-    </simpara>
-   </listitem>
-  </varlistentry>
   <varlistentry>
    <term>
     <constant>LIBXML_NOBLANKS</constant>
@@ -147,6 +120,22 @@
     </simpara>
    </listitem>
   </varlistentry>
+  <varlistentry>
+   <term>
+    <constant>LIBXML_NOXMLDECL</constant>
+     (<type>integer</type>)
+   </term>
+   <listitem>
+    <simpara>
+     Drop the XML declaration when saving a document
+    </simpara>
+    <note>
+     <para>
+      Only available in Libxml &gt;= 2.6.21
+     </para>
+    </note>
+   </listitem>
+  </varlistentry>
   <varlistentry>
    <term>
     <constant>LIBXML_NSCLEAN</constant>
@@ -169,6 +158,50 @@
     </simpara>
    </listitem>
   </varlistentry>
+  <varlistentry>
+   <term>
+    <constant>LIBXML_ERR_ERROR</constant>
+     (<type>integer</type>)
+   </term>
+   <listitem>
+    <simpara>
+     A recoverable error
+    </simpara>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <constant>LIBXML_ERR_FATAL</constant>
+     (<type>integer</type>)
+   </term>
+   <listitem>
+    <simpara>
+     A fatal error
+    </simpara>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <constant>LIBXML_ERR_NONE</constant>
+     (<type>integer</type>)
+   </term>
+   <listitem>
+    <simpara>
+     No errors
+    </simpara>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <constant>LIBXML_ERR_WARNING</constant>
+     (<type>integer</type>)
+   </term>
+   <listitem>
+    <simpara>
+     A simple warning
+    </simpara>
+   </listitem>
+  </varlistentry>
   <varlistentry>
    <term>
     <constant>LIBXML_VERSION</constant>