--- a/src/doc/user/usermanual.sgml
+++ b/src/doc/user/usermanual.sgml
@@ -366,6 +366,39 @@
in the <command>recoll</command> GUI. It is stored in the
<filename>missing</filename> text file inside the configuration
directory.</para>
+
+ <para>By default, &RCL; will try to index any file type that
+ it has a way to read. This is sometimes not desirable, and
+ there are ways to either exclude some types, or on the
+ contrary to define a positive list of types to be
+ indexed. In the latter case, any type not in the list will
+ be ignored.</para>
+ <para>Excluding types can be done by adding name patterns to
+ the <literal>skippedNames</literal> list, which can be done
+ from the GUI Index configuration menu. It is also possible
+ to exclude a mime type independantly of the file name by
+ associating it with the <filename>rclnull</filename>
+ filter. This can be done by editing
+ the <link linkend="RCL.INSTALL.CONFIG.MIMECONF">
+ <filename>mimeconf</filename> configuration
+ file</link>.</para>
+
+ <para>In order to define a positive list, You need to edit the
+ <link linkend="RCL.INSTALL.CONFIG.RECOLLCONF">main
+ configuration file
+ (<filename>recoll.conf</filename>)</link> and set
+ the <literal>indexedmimetypes</literal> configuration
+ variable. Example:<programlisting>
+indexedmimetypes = text/html application/pdf
+ </programlisting>
+ There is no GUI way to do this, because this option runs a
+ bit contrary to &RCL; main goal which is to help you find
+ information, independantly of how it may be stored.
+ </para>
+
+
+
+
</sect2>