added f signal example

Author: tjingboem

opcodes/opcode.xml

@@ -90,7 +90,7 @@
     </para>
 
     <para>
-      <emphasis>intypes</emphasis> -- list of input types, any combination of the characters: a,f, k, O, P, V, K, i, o, p, and j. A single 0 character can be used if there are no input arguments. Double quotes and delimiter characters (e.g. comma) are <emphasis>not</emphasis> needed.
+      <emphasis>intypes</emphasis> -- list of input types, any combination of the characters: a, f, k, O, P, V, K, i, o, p, and j. A single 0 character can be used if there are no input arguments. Double quotes and delimiter characters (e.g. comma) are <emphasis>not</emphasis> needed.
     </para>
 
     <para>
@@ -412,6 +412,16 @@ xinarg1 [, xinarg2] [, xinarg3] ... [xinargN]  <emphasis role="opc">xin</emphasi
         <xi:include href="examples-xml/opcode_example.csd.xml" xmlns:xi="http://www.w3.org/2001/XInclude"/>
       </example>
     </para>
+
+    <para>
+      Here is another example of a user-defined opcode. It uses the file
+      <ulink
+          url="examples/opcode_f.csd"><citetitle>opcode_f.csd</citetitle></ulink>.
+      <example>
+        <title>Second example of a user-defined opcode.</title>
+        <xi:include href="examples-xml/opcode_f.csd.xml" xmlns:xi="http://www.w3.org/2001/XInclude"/>
+      </example>
+    </para>
   </refsect1>
 
   <refsect1>