diff --git a/reference/datetime/functions/strftime.xml b/reference/datetime/functions/strftime.xml
index b7c6870392..c203078495 100644
--- a/reference/datetime/functions/strftime.xml
+++ b/reference/datetime/functions/strftime.xml
@@ -320,6 +320,12 @@
         example below illustrates how to write a cross platform compatible function.
        </simpara>
       </warning>
+      <warning>
+       <simpara>
+        <emphasis>Mac OS X only:</emphasis> The <literal>%P</literal> modifier 
+        is not supported in the Mac OS X implementation of this function.
+       </simpara>
+      </warning>
      </listitem>
     </varlistentry>