diff --git a/apps/opencs/model/doc/saving.cpp b/apps/opencs/model/doc/saving.cpp
index 27d21635e..337784765 100644
--- a/apps/opencs/model/doc/saving.cpp
+++ b/apps/opencs/model/doc/saving.cpp
@@ -65,7 +65,10 @@ CSMDoc::Saving::Saving (Document& document, const boost::filesystem::path& proje
 
     appendStage (new WriteRefIdCollectionStage (mDocument, mState));
 
+    appendStage (new CollectionReferencesStage (mDocument, mState));
 
+
+    // close file and clean up
     appendStage (new CloseSaveStage (mState));
 
     appendStage (new FinalSavingStage (mDocument, mState));
diff --git a/apps/opencs/model/doc/savingstages.cpp b/apps/opencs/model/doc/savingstages.cpp
index eb93d9047..fc35e21cd 100644
--- a/apps/opencs/model/doc/savingstages.cpp
+++ b/apps/opencs/model/doc/savingstages.cpp
@@ -9,6 +9,8 @@
 
 #include <components/esm/loaddial.hpp>
 
+#include <components/misc/stringops.hpp>
+
 #include "../world/infocollection.hpp"
 
 #include "document.hpp"
@@ -214,6 +216,42 @@ void CSMDoc::WriteFilterStage::perform (int stage, Messages& messages)
 }
 
 
+CSMDoc::CollectionReferencesStage::CollectionReferencesStage (Document& document,
+    SavingState& state)
+: mDocument (document), mState (state)
+{}
+
+int CSMDoc::CollectionReferencesStage::setup()
+{
+    mState.getSubRecords().clear();
+
+    int size = mDocument.getData().getReferences().getSize();
+
+    int steps = size/100;
+    if (size%100) ++steps;
+
+    return steps;
+}
+
+void CSMDoc::CollectionReferencesStage::perform (int stage, Messages& messages)
+{
+    int size = mDocument.getData().getReferences().getSize();
+
+    for (int i=stage*100; i<stage*100+100 && i<size; ++i)
+    {
+        const CSMWorld::Record<CSMWorld::CellRef>& record =
+            mDocument.getData().getReferences().getRecord (i);
+
+        if (record.mState==CSMWorld::RecordBase::State_Deleted ||
+            record.mState==CSMWorld::RecordBase::State_Modified ||
+            record.mState==CSMWorld::RecordBase::State_ModifiedOnly)
+        {
+            mState.getSubRecords()[Misc::StringUtils::lowerCase (record.get().mId)].push_back (i);
+        }
+    }
+}
+
+
 CSMDoc::CloseSaveStage::CloseSaveStage (SavingState& state)
 : mState (state)
 {}
diff --git a/apps/opencs/model/doc/savingstages.hpp b/apps/opencs/model/doc/savingstages.hpp
index c2f0a150a..653f3a957 100644
--- a/apps/opencs/model/doc/savingstages.hpp
+++ b/apps/opencs/model/doc/savingstages.hpp
@@ -163,8 +163,24 @@ namespace CSMDoc
 
             virtual void perform (int stage, Messages& messages);
             ///< Messages resulting from this stage will be appended to \a messages.
+
     };
 
+    class CollectionReferencesStage : public Stage
+    {
+            Document& mDocument;
+            SavingState& mState;
+
+        public:
+
+            CollectionReferencesStage (Document& document, SavingState& state);
+
+            virtual int setup();
+            ///< \return number of steps
+
+            virtual void perform (int stage, Messages& messages);
+            ///< Messages resulting from this stage will be appended to \a messages.
+    };
 
     class CloseSaveStage : public Stage
     {
diff --git a/apps/opencs/model/doc/savingstate.cpp b/apps/opencs/model/doc/savingstate.cpp
index 874214822..294f83049 100644
--- a/apps/opencs/model/doc/savingstate.cpp
+++ b/apps/opencs/model/doc/savingstate.cpp
@@ -25,6 +25,8 @@ void CSMDoc::SavingState::start (Document& document, bool project)
 
     mStream.clear();
 
+    mSubRecords.clear();
+
     if (project)
         mPath = mProjectPath;
     else
@@ -60,4 +62,9 @@ ESM::ESMWriter& CSMDoc::SavingState::getWriter()
 bool CSMDoc::SavingState::isProjectFile() const
 {
     return mProjectFile;
+}
+
+std::map<std::string, std::vector<int> > CSMDoc::SavingState::getSubRecords()
+{
+    return mSubRecords;
 }
\ No newline at end of file
diff --git a/apps/opencs/model/doc/savingstate.hpp b/apps/opencs/model/doc/savingstate.hpp
index 6b4565584..64085bf0d 100644
--- a/apps/opencs/model/doc/savingstate.hpp
+++ b/apps/opencs/model/doc/savingstate.hpp
@@ -2,6 +2,7 @@
 #define CSM_DOC_SAVINGSTATE_H
 
 #include <fstream>
+#include <map>
 
 #include <boost/filesystem/path.hpp>
 
@@ -24,6 +25,7 @@ namespace CSMDoc
             ESM::ESMWriter mWriter;
             boost::filesystem::path mProjectPath;
             bool mProjectFile;
+            std::map<std::string, std::vector<int> > mSubRecords; // record ID, list of subrecords
 
         public:
 
@@ -45,6 +47,8 @@ namespace CSMDoc
 
             bool isProjectFile() const;
             ///< Currently saving project file? (instead of content file)
+
+            std::map<std::string, std::vector<int> > getSubRecords();
     };
 
 
diff --git a/apps/opencs/model/world/ref.cpp b/apps/opencs/model/world/ref.cpp
index 44ffa92b9..d1bd771f8 100644
--- a/apps/opencs/model/world/ref.cpp
+++ b/apps/opencs/model/world/ref.cpp
@@ -1,2 +1,10 @@
 
 #include "ref.hpp"
+
+CSMWorld::CellRef::CellRef()
+{
+    mRefNum.mIndex = 0;
+
+    // special marker: This reference does not have a RefNum assign to it yet.
+    mRefNum.mContentFile = -2;
+}
\ No newline at end of file
diff --git a/apps/opencs/model/world/ref.hpp b/apps/opencs/model/world/ref.hpp
index b60cbd7e4..eb62434cf 100644
--- a/apps/opencs/model/world/ref.hpp
+++ b/apps/opencs/model/world/ref.hpp
@@ -12,6 +12,8 @@ namespace CSMWorld
     {
         std::string mId;
         std::string mCell;
+
+        CellRef();
     };
 }