--- en/appendices/ini.core.xml
+++ en/appendices/ini.core.xml
@@ -1300,6 +1300,24 @@
         './file'</literal> than having PHP always check the current
         directory for every include.
        </para>
+       <note>
+        <para>
+         ENV variables are also accessible inside the .ini
+         files.  As such it is possible to reference the home directory
+         using <constant>${LOGIN}</constant> and <constant>${USER}</constant>.  
+         See the example below.
+        </para>       
+       </note>
+       <para>
+        <example>
+         <title>Unix include_path using ${USER} env variable</title>
+         <programlisting role="php.ini">
+<![CDATA[
+include_path = ".:${USER}/pear/php"
+]]>
+         </programlisting>
+        </example>
+       </para>
       </listitem>
      </varlistentry>