diff --git a/reference/pcre/pattern.syntax.xml b/reference/pcre/pattern.syntax.xml
index 0e44c40903..b089853d0e 100644
--- a/reference/pcre/pattern.syntax.xml
+++ b/reference/pcre/pattern.syntax.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.17 $ -->
+<!-- $Revision: 1.18 $ -->
 <!-- splitted from ./en/functions/pcre.xml, last change in rev 1.2 -->
   <refentry xml:id="reference.pcre.pattern.syntax" xmlns="http://docbook.org/ns/docbook">
    <refnamediv>
@@ -486,6 +486,14 @@
        <term><emphasis>\D</emphasis></term>
        <listitem><simpara>any character that is not a decimal digit</simpara></listitem>
       </varlistentry>
+      <varlistentry>
+       <term><emphasis>\h</emphasis></term>
+       <listitem><simpara>any horizontal whitespace character (since PHP 5.2.4)</simpara></listitem>
+      </varlistentry>
+      <varlistentry>
+       <term><emphasis>\H</emphasis></term>
+       <listitem><simpara>any character that is not a horizontal whitespace character (since PHP 5.2.4)</simpara></listitem>
+      </varlistentry>
       <varlistentry>
        <term><emphasis>\s</emphasis></term>
        <listitem><simpara>any whitespace character</simpara></listitem>
@@ -494,6 +502,14 @@
        <term><emphasis>\S</emphasis></term>
        <listitem><simpara>any character that is not a whitespace character</simpara></listitem>
       </varlistentry>
+      <varlistentry>
+       <term><emphasis>\v</emphasis></term>
+       <listitem><simpara>any vertical whitespace character (since PHP 5.2.4)</simpara></listitem>
+      </varlistentry>
+      <varlistentry>
+       <term><emphasis>\V</emphasis></term>
+       <listitem><simpara>any character that is not a vertical whitespace character (since PHP 5.2.4)</simpara></listitem>
+      </varlistentry>
       <varlistentry>
        <term><emphasis>\w</emphasis></term>
        <listitem><simpara>any "word" character</simpara></listitem>
@@ -609,6 +625,15 @@
       the string.
      </para>
      
+     <para>
+      <literal>\K</literal> can be used to reset the match start since
+      PHP 5.2.4. For example, the pattern <literal>foo\Kbar</literal> matches
+      "foobar", but reports that it has matched "bar". The use of
+      <literal>\K</literal> does not interfere with the setting of captured
+      substrings. For example, when the pattern <literal>(foo)\Kbar</literal>
+      matches "foobar", the first substring is still set to "foo".
+     </para>
+     
     </refsect2>
 
     <refsect2 xml:id="regexp.reference.unicode">
@@ -1331,6 +1356,13 @@
      reference.  This  can  be  done using alternation, as in the
      example above, or by a quantifier with a minimum of zero.
      </para>
+     
+     <para>
+      Back references to the named subpatterns can be achieved by
+      <literal>(?P=name)</literal> or, since PHP 5.2.4, also by
+      <literal>\k&lt;name&gt;</literal>, <literal>\k'name'</literal> or
+      <literal>\k{name}</literal>.
+     </para>
     </refsect2>
 
     <refsect2 xml:id="regexp.reference.assertions">