diff --git a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/MuonEventTPCnv/MuonPrepRawData/MMPrepData_p1.h b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/MuonEventTPCnv/MuonPrepRawData/MMPrepData_p1.h
index f6382d41025b08df4a146eaf362f014168509acb..9e9faa0037fd0b21fe491408893b01e90f0ad277 100644
--- a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/MuonEventTPCnv/MuonPrepRawData/MMPrepData_p1.h
+++ b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/MuonEventTPCnv/MuonPrepRawData/MMPrepData_p1.h
@@ -43,7 +43,7 @@ namespace Muon
 	std::vector<float>        m_stripDriftDist;
 	std::vector<Amg::MatrixX> m_stripDriftErrors;
 
-  int m_author; // contains the info about which cluster builder tool produced the PRD
+  int m_author = 0; // contains the info about which cluster builder tool produced the PRD
         
         //@}
         
diff --git a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonPrepRawData/MMPrepDataCnv_p1.cxx b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonPrepRawData/MMPrepDataCnv_p1.cxx
index 9afba6d518f4fb308b31fff05e12bb8762f61323..da3beb2151df3838d5a4d8fd3bee7cd48938b4fd 100644
--- a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonPrepRawData/MMPrepDataCnv_p1.cxx
+++ b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/src/MuonPrepRawData/MMPrepDataCnv_p1.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "MuonPrepRawData/MMPrepData.h"
@@ -58,6 +58,7 @@ persToTrans( const Muon::MMPrepData_p1 *persObj, Muon::MMPrepData *transObj,MsgS
 				transObj->identify(),
                                 transObj->detectorElement(),
                                 log);
+  transObj->setAuthor(static_cast<Muon::MMPrepData::Author>(persObj->m_author));
 }
 
 void MMPrepDataCnv_p1::
diff --git a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/test/MMPrepDataCnv_p1_test.cxx b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/test/MMPrepDataCnv_p1_test.cxx
index bd2f4670d611597afa73154ed4950eb780d40ef3..edd4baa0eb175f6d0e1dfb3f97ab85a8fa13900e 100644
--- a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/test/MMPrepDataCnv_p1_test.cxx
+++ b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/test/MMPrepDataCnv_p1_test.cxx
@@ -1,8 +1,6 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
-
-// $Id$
 /**
  * @file MuonEventTPCnv/test/MMPrepDataCnv_p1_test.cxx
  * @author scott snyder <snyder@bnl.gov>
@@ -41,6 +39,7 @@ void compare (const Muon::MuonCluster& p1,
 void compare (const Muon::MMPrepData& p1,
               const Muon::MMPrepData& p2)
 {
+  assert (p1.author() == p2.author());
   compare (static_cast<const Muon::MuonCluster&>(p1),
            static_cast<const Muon::MuonCluster&>(p2));
   assert (p1.detectorElement() == p2.detectorElement());
@@ -80,6 +79,7 @@ void test1()
                            rdoList,
                            new Amg::MatrixX(cov),
                            nullptr);
+  trans1.setAuthor (Muon::MMPrepData::ConstraintuTPCClusterBuilder);
                           
   testit (trans1);
 }
diff --git a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/test/MMPrepDataContainerCnv_p1_test.cxx b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/test/MMPrepDataContainerCnv_p1_test.cxx
index 3dbbe5d65df9a8b70109d07621d565ed70a6d6a6..5f4a64b2b19eeee1880c6ccc77db6ec87171444c 100644
--- a/MuonSpectrometer/MuonCnv/MuonEventTPCnv/test/MMPrepDataContainerCnv_p1_test.cxx
+++ b/MuonSpectrometer/MuonCnv/MuonEventTPCnv/test/MMPrepDataContainerCnv_p1_test.cxx
@@ -42,6 +42,7 @@ void compare (const Muon::MuonCluster& p1,
 void compare (const Muon::MMPrepData& p1,
               const Muon::MMPrepData& p2)
 {
+  assert (p1.author() == p2.author());
   assert (p1.identify() == p2.identify());
   compare (static_cast<const Muon::MuonCluster&>(p1),
            static_cast<const Muon::MuonCluster&>(p2));
@@ -117,6 +118,7 @@ makeclusts (const MuonGM::MuonDetectorManager& muo_dd)
          rdoList,
          new Amg::MatrixX(cov),
          muo_dd.getMMReadoutElement (clusId));
+      cl->setAuthor (Muon::MMPrepData::ProjectionClusterBuilder);
       coll->push_back (std::move (cl));
     }
     assert(cont->addCollection (coll.release(), hash));
diff --git a/MuonSpectrometer/MuonReconstruction/MuonRecEvent/MuonPrepRawData/src/MMPrepData.cxx b/MuonSpectrometer/MuonReconstruction/MuonRecEvent/MuonPrepRawData/src/MMPrepData.cxx
index 67a2a0f867ba3a8b00c5a209e89a3fa3a1637382..9083f4d7abe22850d4759c254d7b870ab197973d 100755
--- a/MuonSpectrometer/MuonReconstruction/MuonRecEvent/MuonPrepRawData/src/MMPrepData.cxx
+++ b/MuonSpectrometer/MuonReconstruction/MuonRecEvent/MuonPrepRawData/src/MMPrepData.cxx
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "MuonPrepRawData/MMPrepData.h"
@@ -31,7 +31,8 @@ namespace Muon
     m_stripTimes(stripTimes),
     m_stripCharges(stripCharges),
     m_stripDriftDist(),
-    m_stripDriftErrors()
+    m_stripDriftErrors(),
+    m_author (SimpleClusterBuilder)
   { }
 
   MMPrepData::MMPrepData( const Identifier& RDOId,
@@ -51,7 +52,8 @@ namespace Muon
     m_chisqProb(0.0),
     m_stripNumbers(),
     m_stripTimes(),
-    m_stripCharges()
+    m_stripCharges(),
+    m_author (SimpleClusterBuilder)
   { }
 
   MMPrepData::MMPrepData( const Identifier& RDOId,
@@ -72,7 +74,8 @@ namespace Muon
     m_chisqProb(0.0),
     m_stripNumbers(),
     m_stripTimes(),
-    m_stripCharges()
+    m_stripCharges(),
+    m_author (SimpleClusterBuilder)
   { }
 
   MMPrepData::MMPrepData( const Identifier& RDOId,
@@ -92,7 +95,8 @@ namespace Muon
     m_stripTimes(),
     m_stripCharges(),
     m_stripDriftDist(),
-    m_stripDriftErrors()
+    m_stripDriftErrors(),
+    m_author (SimpleClusterBuilder)
   { }
 
   // Destructor:
@@ -114,7 +118,8 @@ namespace Muon
     m_stripTimes(),
     m_stripCharges(),
     m_stripDriftDist(),
-    m_stripDriftErrors()    
+    m_stripDriftErrors(),
+    m_author (SimpleClusterBuilder)
   { }
 
   //copy constructor:
@@ -130,7 +135,8 @@ namespace Muon
     m_stripTimes(RIO.m_stripTimes),
     m_stripCharges(RIO.m_stripCharges),
     m_stripDriftDist(RIO.m_stripDriftDist),
-    m_stripDriftErrors(RIO.m_stripDriftErrors)
+    m_stripDriftErrors(RIO.m_stripDriftErrors),
+    m_author(RIO.m_author)
   { }
 
   //move constructor:
@@ -146,7 +152,8 @@ namespace Muon
     m_stripTimes(RIO.m_stripTimes),
     m_stripCharges(RIO.m_stripCharges),
     m_stripDriftDist(RIO.m_stripDriftDist),
-    m_stripDriftErrors(RIO.m_stripDriftErrors)
+    m_stripDriftErrors(RIO.m_stripDriftErrors),
+    m_author(RIO.m_author)
   { }
 
   /// set the micro-tpc quantities
@@ -185,6 +192,7 @@ namespace Muon
 	m_stripCharges = RIO.m_stripCharges;
 	m_stripDriftDist = RIO.m_stripDriftDist;
 	m_stripDriftErrors = RIO.m_stripDriftErrors;
+	m_author = RIO.m_author;
       }
     return *this;
 
@@ -207,6 +215,7 @@ namespace Muon
 	m_stripCharges = RIO.m_stripCharges;
 	m_stripDriftDist = RIO.m_stripDriftDist;
 	m_stripDriftErrors = RIO.m_stripDriftErrors;
+	m_author = RIO.m_author;
       }
     return *this;