diff --git a/src/doc/user/usermanual.sgml b/src/doc/user/usermanual.sgml
index 131556c2..0436c5a0 100644
--- a/src/doc/user/usermanual.sgml
+++ b/src/doc/user/usermanual.sgml
@@ -1558,7 +1558,24 @@ fvwm
 	  <listitem><formalpara><title>%U</title><para>Url</para></formalpara>
 	  </listitem>
 	</itemizedlist>
-        The default value for the string is:
+
+	In addition to the predefined values above, all strings like
+	<literal>%(fieldname)</literal> will be replaced by the value
+	of the field named <literal>fieldname</literal> for this
+	document. Only stored fields can be accessed in this way, the
+	value of indexed but not stored fields is not known at this
+	point (see <link linkend="rcl.program.fields">field
+	configuration</link>). There are currently very few fields
+	stored by default, apart from the values above (only
+	<literal>author</literal>), so this feature will need some
+	custom local configuration to be useful. For example, you
+	could look at the fields for the document types of interest
+	(use the right-click menu inside the preview window), and add
+	what you want to the list of stored fields. A candidate
+	example would be the <literal>recipient</literal> field
+	which is generated by the message filters.</para>
+
+        <para>The default value for the paragraph format string is:
         <programlisting>&lt;img src="%I" align="left">%R %S %L &amp;nbsp;&amp;nbsp;&lt;b>%T&lt;/b>&lt;br>
 %M&amp;nbsp;%D&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;i>%U&lt;/i>&lt;br>
 %A %K
@@ -2008,7 +2025,9 @@ text/rtf = exec unrtf --nopict --html; charset=iso-8859-1; mimetype=text/html
       <para>A field becomes stored by appearing in
       the <literal>[stored]</literal> section of the
       <filename>fields</filename> file.</para>
-
+      
+      <para>See the comments inside the <filename>fields</filename>
+            for more details.</para>
     </sect1>