diff --git a/miniupnpd/upnppinhole.h b/miniupnpd/upnppinhole.h
index 4fd509a..fbfe1f2 100644
--- a/miniupnpd/upnppinhole.h
+++ b/miniupnpd/upnppinhole.h
@@ -1,4 +1,4 @@
-/* $Id: upnppinhole.h,v 1.1 2012/05/01 20:08:22 nanard Exp $ */
+/* $Id: upnppinhole.h,v 1.2 2012/09/18 08:29:49 nanard Exp $ */
 /* MiniUPnP project
  * http://miniupnp.free.fr/ or http://miniupnp.tuxfamily.org/
  * (c) 2006-2012 Thomas Bernard
@@ -57,7 +57,9 @@ int
 upnp_check_pinhole_working(const char * uid, char * eaddr, char * iaddr, unsigned short * eport, unsigned short * iport, char * protocol, int * rulenum_used);
 #endif
 
-/* ? */
+/* return the number of expired pinhole removed
+ * write timestamp to next pinhole to exprire to next_timestamp
+ * next_timestamp is left untouched if there is no pinhole lest */
 int
 upnp_clean_expired_pinholes(unsigned int * next_timestamp);