diff --git a/doc/musrSim.pdf b/doc/musrSim.pdf
index f2c8462..26e1340 100644
Binary files a/doc/musrSim.pdf and b/doc/musrSim.pdf differ
diff --git a/doc/musrSim.tex b/doc/musrSim.tex
index ec1e749..f3d9efc 100644
--- a/doc/musrSim.tex
+++ b/doc/musrSim.tex
@@ -620,6 +620,20 @@ Three special volumes ``Target, M0, M1 and M2''.
 	The five last parameters correspond to the Geant4 methods
 	``SetMaxAllowedStep'', ``SetUserMaxTrackLength'', ``SetUserMaxTime'',
 	``SetUserMinEkine'' and ``SetUserMinRange''.
+	{\bf NOTE THAT  G4StepLimiter AND/OR G4UserSpecialCuts HAS TO BE DEFINED FOR THE
+	REQUIRED PARTICLE TYPES BEFORE CALLING THIS COMMAND!}\\
+	(E.g.:\ ``/musr/command process addProcess        mu+   G4StepLimiter      -1 -1 5'')\\
+	See chapter ``5.7.  User Limits'' (namely ``5.7.2.  Processes co-working with G4UserLimits'')
+	of the Geant User Manual for more details about this issue.
+
+	The user can set G4UserLimits to logical volume and/or to a region.
+	{\bf At the moment, ``/musr/command SetUserLimits'' in musrSim supports the G4UserLimits
+	in logical volumes only, not in the G4Regions.}
+	User limits assigned to logical volume do not propagate to daughter volumes, 
+	while User limits assigned to region propagate to daughter volumes unless 
+	daughters belong to another region. If both logical volume and associated 
+	region have user limits, those of logical volume win.
+
 
 \item{\bf /musr/command storeOnlyEventsWithHits false}\\
 	By default, only the events in which at least one hit in an active
diff --git a/src/musrPhysicsList.cc b/src/musrPhysicsList.cc
index d9cd25e..00a3283 100644
--- a/src/musrPhysicsList.cc
+++ b/src/musrPhysicsList.cc
@@ -42,6 +42,9 @@
 //
 #include "musrParameters.hh"
 #include "musrErrorMessage.hh"
+// cks 2009-06-08   G4StepLimiter and/or G4UserSpecialCuts are needed to activate the "G4UserLimits"
+#include "G4StepLimiter.hh"
+#include "G4UserSpecialCuts.hh"
 
 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
@@ -296,6 +299,9 @@ void musrPhysicsList::ConstructEM()
 	  else if (stringProcessName=="G4MuIonisation")      pManager->AddProcess(new G4MuIonisation,nr1,nr2,nr3);
 	  else if (stringProcessName=="G4MuBremsstrahlung")      pManager->AddProcess(new G4MuBremsstrahlung,nr1,nr2,nr3);
 	  else if (stringProcessName=="G4MuPairProduction")      pManager->AddProcess(new G4MuPairProduction,nr1,nr2,nr3);
+          // cks 2009-06-08   G4StepLimiter and/or G4UserSpecialCuts are needed to activate the "G4UserLimits"
+	  else if (stringProcessName=="G4StepLimiter")      pManager->AddProcess(new G4StepLimiter,nr1,nr2,nr3);
+	  else if (stringProcessName=="G4UserSpecialCuts")      pManager->AddProcess(new G4UserSpecialCuts,nr1,nr2,nr3);
 	  //	  else if (stringProcessName=="G4DecayWithSpin")      pManager->AddProcess(new G4DecayWithSpin,nr1,nr2,nr3);
 	  //	  else if (stringProcessName=="G4hIonisation")      pManager->AddProcess(new G4hIonisation,nr1,nr2,nr3);
 	  //	  else if (stringProcessName=="G4hLowEnergyIonisation")      pManager->AddProcess(new G4hLowEnergyIonisation,nr1,nr2,nr3);