diff --git a/functions/pcre.xml b/functions/pcre.xml
index c25ae91463..f6e50e1d33 100644
--- a/functions/pcre.xml
+++ b/functions/pcre.xml
@@ -6,10 +6,11 @@
    <para>
     The syntax for patterns used in these functions closely resembles
     Perl. The expression should be enclosed in the delimiters, a
-    forward slash (/),  for example.  Any character can be used for
+    forward slash (/), for example.  Any character can be used for
     delimiter as long as it's not alphanumeric or backslash (\). If
     the delimiter character has to be used in the expression itself,
-    it needs to be escaped by backslash.
+    it needs to be escaped by backslash. Since PHP 4.0.4, you can also use
+    Perl-style (), {}, [], and &lt;&gt; matching delimiters.
    </para>
    <para>
     The ending delimiter may be followed by various modifiers that
@@ -23,6 +24,7 @@
       <listitem><simpara>/&lt;\/\w+>/</simpara></listitem>
       <listitem><simpara>|(\d{3})-\d+|Sm</simpara></listitem>
       <listitem><simpara>/^(?i)php[34]/</simpara></listitem>
+      <listitem><simpara>{^\s+(\s+)?$}</simpara></listitem>
      </itemizedlist>
     </example>
    </para>
@@ -362,6 +364,13 @@ part 3: &lt;/a&gt;
      code string, otherwise PHP will complain about a parse error at
      the line containing <function>preg_replace</function>.
     </para>
+    <para>
+    </literal>/F</literal> modifier means that the
+    <parameter>replacement</parameter> is taken to be a function name. This
+    function will be called and passed an array of matched elements in the
+    subject string. The function should return the replacement string. This
+    modifier was added in PHP 4.0.4.
+    </para>
     <para>
      <example>
       <title>Replacing several values</title>
@@ -694,7 +703,8 @@ $fl_array = preg_grep ("/^(\d+)?\.\d+$/", $array);
 	  If this modifier is set, <function>preg_replace</function>
 	  does normal substitution of backreferences in the
 	  replacement string, evaluates it as PHP code, and uses the
-	  result for replacing the search string.
+	  result for replacing the search string. This modifier cannot be used along
+      with <literal>/F modifier</literal>.
 	 </simpara>
 	 <simpara>
 	  Only <function>preg_replace</function> uses this modifier;
@@ -702,6 +712,23 @@ $fl_array = preg_grep ("/^(\d+)?\.\d+$/", $array);
 	 </simpara>
 	</listitem>
        </varlistentry>
+       <varlistentry>
+	<term><emphasis>F</emphasis></term>
+	<listitem>
+	 <simpara>
+	  If this modifier is set, <function>preg_replace</function>
+      treats the replacement parameter as a function name that should be called
+      to provide the replacement string. The function is passed an array of
+      matched elements in the subject string. This modifier cannot be used along
+      with <literal>/e modifier</literal>.
+	 </simpara>
+	 <simpara>
+	  Only <function>preg_replace</function> uses this modifier;
+	  it is ignored by other PCRE functions. This modifier was added in PHP
+      4.0.4.
+	 </simpara>
+	</listitem>
+       </varlistentry>
        <varlistentry>
 	<term><emphasis>A</emphasis> (PCRE_ANCHORED)</term>
 	<listitem>