Index: trunk/MagicSoft/include-Classes/MMcFormat/MMcTrigHeader.cxx
===================================================================
--- trunk/MagicSoft/include-Classes/MMcFormat/MMcTrigHeader.cxx	(revision 1313)
+++ trunk/MagicSoft/include-Classes/MMcFormat/MMcTrigHeader.cxx	(revision 1314)
@@ -11,6 +11,18 @@
 // The information is saved only once, whatever the
 // number of events is
- 
-
+//
+// This is the second version of this output class. Old root files, which have
+// a previous version of this class, are still compatibles and can be used.
+// But of course, you can no try to get infromatino in these old files about
+// the new data members.
+//
+// The following data member have been introduced in this second version 
+// and they do not exist in the previous one:
+//
+//   Float_t  fElecNoiseTrig;  The width of the gaussian noise is that times
+//                             the amplitude of the single phe response 
+//                             for the trigger 
+//
+/////////////////////////
 
 ClassImp(MMcTrigHeader);