Index: trunk/FACT++/src/fitsdump.cc
===================================================================
--- trunk/FACT++/src/fitsdump.cc	(revision 12905)
+++ trunk/FACT++/src/fitsdump.cc	(revision 12906)
@@ -677,5 +677,5 @@
         ("limit",       var<size_t>(size_t(0)),     "Limit for the maximum number of rows to read (0=unlimited)")
 #ifdef HAVE_ROOT
-        ("filter,r",    var<string>(""),            "Filter to restrict the selection of events (does not work with stat and minmax yet)")
+        ("filter,r",    var<string>(""),            "Filter to restrict the selection of events (e.g. '[0]>10 && [0]<20';  does not work with stat and minmax yet)")
 #endif
         ;