diff --git a/sw/source/core/inc/UndoAttribute.hxx b/sw/source/core/inc/UndoAttribute.hxx
index ddc3289bb112..46dee451bae1 100644
--- a/sw/source/core/inc/UndoAttribute.hxx
+++ b/sw/source/core/inc/UndoAttribute.hxx
@@ -226,12 +226,12 @@ class SwUndoChangeFootNote : public SwUndo, private SwUndRng
     SAL_WNODEPRECATED_DECLARATIONS_PUSH
     const ::std::auto_ptr<SwHistory> m_pHistory;
     SAL_WNODEPRECATED_DECLARATIONS_POP
-    const String m_Text;
+    const OUString m_Text;
     const sal_uInt16 m_nNumber;
     const bool m_bEndNote;
 
 public:
-    SwUndoChangeFootNote( const SwPaM& rRange, const String& rTxt,
+    SwUndoChangeFootNote( const SwPaM& rRange, const OUString& rTxt,
                           sal_uInt16 nNum, bool bIsEndNote );
     virtual ~SwUndoChangeFootNote();
 
diff --git a/sw/source/core/inc/UndoCore.hxx b/sw/source/core/inc/UndoCore.hxx
index 67d2e78f44fc..fd9c201c26ed 100644
--- a/sw/source/core/inc/UndoCore.hxx
+++ b/sw/source/core/inc/UndoCore.hxx
@@ -108,7 +108,7 @@ private:
 
 class SwUndoFmtColl : public SwUndo, private SwUndRng
 {
-    String aFmtName;
+    OUString aFmtName;
     SwHistory* pHistory;
     SwFmtColl* pFmtColl;
     // for correct <ReDo(..)> and <Repeat(..)>
@@ -213,8 +213,8 @@ const int nUndoStringLength = 20;
 
    @return the shortened string
  */
-String
-ShortenString(const String & rStr, xub_StrLen nLength, const String & rFillStr);
+OUString
+ShortenString(const OUString & rStr, xub_StrLen nLength, const OUString & rFillStr);
 /**
    Denotes special characters in a string.
 
@@ -233,7 +233,7 @@ ShortenString(const String & rStr, xub_StrLen nLength, const String & rFillStr);
 
    @return the denoted string
 */
-String DenoteSpecialCharacters(const String & rStr);
+OUString DenoteSpecialCharacters(const OUString & rStr);
 
 #endif // SW_UNDOCORE_HXX
 
diff --git a/sw/source/core/inc/UndoDelete.hxx b/sw/source/core/inc/UndoDelete.hxx
index 3cec55373a8d..39b20f0a40c1 100644
--- a/sw/source/core/inc/UndoDelete.hxx
+++ b/sw/source/core/inc/UndoDelete.hxx
@@ -37,13 +37,13 @@ class SwUndoDelete
     , private SwUndoSaveCntnt
 {
     SwNodeIndex* pMvStt;            // Position of Nodes in UndoNodes-Array
-    String *pSttStr, *pEndStr;
+    OUString *pSttStr, *pEndStr;
     SwRedlineData* pRedlData;
     SwRedlineSaveDatas* pRedlSaveData;
     ::boost::shared_ptr< ::sfx2::MetadatableUndo > m_pMetadataUndoStart;
     ::boost::shared_ptr< ::sfx2::MetadatableUndo > m_pMetadataUndoEnd;
 
-    String sTableName;
+    OUString sTableName;
 
     sal_uLong nNode;
     sal_uLong nNdDiff;           // difference of Nodes before/after Delete
@@ -92,7 +92,7 @@ public:
     void SetPgBrkFlags( sal_Bool bPageBreak, sal_Bool bPageDesc )
         { bResetPgDesc = bPageDesc; bResetPgBrk = bPageBreak; }
 
-    void SetTableName(const String & rName);
+    void SetTableName(const OUString & rName);
 
     // SwUndoTblCpyTbl needs this information:
     sal_Bool IsDelFullPara() const { return bDelFullPara; }
diff --git a/sw/source/core/inc/UndoInsert.hxx b/sw/source/core/inc/UndoInsert.hxx
index 04b594938fcd..a235a992aa42 100644
--- a/sw/source/core/inc/UndoInsert.hxx
+++ b/sw/source/core/inc/UndoInsert.hxx
@@ -35,7 +35,7 @@ class SwUndoInsert: public SwUndo, private SwUndoSaveCntnt
 {
     /// start of Content in UndoNodes for Redo
     ::boost::scoped_ptr<SwNodeIndex> m_pUndoNodeIndex;
-    String *pTxt, *pUndoTxt;
+    OUString *pTxt, *pUndoTxt;
     SwRedlineData* pRedlData;
     sal_uLong nNode;
     xub_StrLen nCntnt, nLen;
@@ -52,7 +52,7 @@ class SwUndoInsert: public SwUndo, private SwUndoSaveCntnt
     SwDoc * pDoc;
 
     void Init(const SwNodeIndex & rNode);
-    String * GetTxtFromDoc() const;
+    OUString * GetTxtFromDoc() const;
 
 public:
     SwUndoInsert( const SwNodeIndex& rNode, xub_StrLen nCntnt, xub_StrLen nLen,
@@ -162,11 +162,11 @@ class SwUndoInsertLabel : public SwUndo
         } NODE;
     };
 
-    String sText;
+    OUString sText;
     // #i39983# the separator is drawn with a character style
-    String sSeparator;
-    String sNumberSeparator;
-    String sCharacterStyle;
+    OUString sSeparator;
+    OUString sNumberSeparator;
+    OUString sCharacterStyle;
     // #i26791# - re-store of drawing object position no longer needed
     sal_uInt16 nFldId;
     SwLabelType eType;
@@ -176,12 +176,12 @@ class SwUndoInsertLabel : public SwUndo
     sal_Bool bCpyBrd        :1;
 
 public:
-    SwUndoInsertLabel( const SwLabelType eTyp, const String &rText,
+    SwUndoInsertLabel( const SwLabelType eTyp, const OUString &rText,
     // #i39983# the separator is drawn with a character style
-                        const String& rSeparator,
-                        const String& rNumberSeparator, //#i61007# order of captions
+                        const OUString& rSeparator,
+                        const OUString& rNumberSeparator, //#i61007# order of captions
                         const sal_Bool bBefore, const sal_uInt16 nId,
-                        const String& rCharacterStyle,
+                        const OUString& rCharacterStyle,
                         const sal_Bool bCpyBrd );
     virtual ~SwUndoInsertLabel();
 
diff --git a/sw/source/core/inc/UndoNumbering.hxx b/sw/source/core/inc/UndoNumbering.hxx
index f54996bef69b..5dd6b72a2848 100644
--- a/sw/source/core/inc/UndoNumbering.hxx
+++ b/sw/source/core/inc/UndoNumbering.hxx
@@ -33,7 +33,7 @@ class SwUndoInsNum : public SwUndo, private SwUndRng
     SwHistory* pHistory;
     sal_uLong nSttSet;
     SwNumRule* pOldNumRule;
-    String sReplaceRule;
+    OUString sReplaceRule;
     sal_uInt16 nLRSavePos;
 
 public:
@@ -41,7 +41,7 @@ public:
     SwUndoInsNum( const SwNumRule& rOldRule, const SwNumRule& rNewRule,
                   SwUndoId nUndoId = UNDO_INSFMTATTR );
     SwUndoInsNum( const SwPosition& rPos, const SwNumRule& rRule,
-                            const String& rReplaceRule );
+                            const OUString& rReplaceRule );
 
     virtual ~SwUndoInsNum();
 
diff --git a/sw/source/core/inc/UndoOverwrite.hxx b/sw/source/core/inc/UndoOverwrite.hxx
index 54365d104e65..c21857bd5cc8 100644
--- a/sw/source/core/inc/UndoOverwrite.hxx
+++ b/sw/source/core/inc/UndoOverwrite.hxx
@@ -33,7 +33,7 @@ namespace utl {
 
 class SwUndoOverwrite: public SwUndo, private SwUndoSaveCntnt
 {
-    String aDelStr, aInsStr;
+    OUString aDelStr, aInsStr;
     SwRedlineSaveDatas* pRedlSaveData;
     sal_uLong nSttNode;
     xub_StrLen nSttCntnt;
diff --git a/sw/source/core/inc/UndoSort.hxx b/sw/source/core/inc/UndoSort.hxx
index 501ff59968ae..0e5490ce8d0b 100644
--- a/sw/source/core/inc/UndoSort.hxx
+++ b/sw/source/core/inc/UndoSort.hxx
@@ -37,14 +37,14 @@ struct SwSortUndoElement
             sal_uLong nSource, nTarget;
         } TXT;
         struct {
-            String *pSource, *pTarget;
+            OUString *pSource, *pTarget;
         } TBL;
     } SORT_TXT_TBL;
 
-    SwSortUndoElement( const String& aS, const String& aT )
+    SwSortUndoElement( const OUString& aS, const OUString& aT )
     {
-        SORT_TXT_TBL.TBL.pSource = new String( aS );
-        SORT_TXT_TBL.TBL.pTarget = new String( aT );
+        SORT_TXT_TBL.TBL.pSource = new OUString( aS );
+        SORT_TXT_TBL.TBL.pTarget = new OUString( aT );
     }
     SwSortUndoElement( sal_uLong nS, sal_uLong nT )
     {
@@ -77,7 +77,7 @@ public:
     virtual void RedoImpl( ::sw::UndoRedoContext & );
     virtual void RepeatImpl( ::sw::RepeatContext & );
 
-    void Insert( const String& rOrgPos, const String& rNewPos );
+    void Insert( const OUString& rOrgPos, const OUString& rNewPos );
     void Insert( sal_uLong nOrgPos, sal_uLong nNewPos );
 };
 
diff --git a/sw/source/core/inc/UndoTable.hxx b/sw/source/core/inc/UndoTable.hxx
index 61a8d271fdb0..2788d83d3095 100644
--- a/sw/source/core/inc/UndoTable.hxx
+++ b/sw/source/core/inc/UndoTable.hxx
@@ -49,7 +49,7 @@ class SwTableSortBoxes;
 
 class SwUndoInsTbl : public SwUndo
 {
-    String sTblNm;
+    OUString sTblNm;
     SwInsertTableOptions aInsTblOpts;
     SwDDEFieldType* pDDEFldType;
     std::vector<sal_uInt16> *pColWidth;
@@ -63,7 +63,7 @@ public:
     SwUndoInsTbl( const SwPosition&, sal_uInt16 nCols, sal_uInt16 nRows,
                     sal_uInt16 eAdjust, const SwInsertTableOptions& rInsTblOpts,
                     const SwTableAutoFmt* pTAFmt, const std::vector<sal_uInt16> *pColArr,
-                  const String & rName);
+                  const OUString & rName);
 
     virtual ~SwUndoInsTbl();
 
@@ -76,7 +76,7 @@ public:
 
 class SwUndoTxtToTbl : public SwUndo, public SwUndRng
 {
-    String sTblNm;
+    OUString sTblNm;
     SwInsertTableOptions aInsTblOpts;
     std::vector<sal_uLong>* pDelBoxes;
     SwTableAutoFmt* pAutoFmt;
@@ -102,7 +102,7 @@ public:
 
 class SwUndoTblToTxt : public SwUndo
 {
-    String sTblNm;
+    OUString sTblNm;
     SwDDEFieldType* pDDEFldType;
     _SaveTable* pTblSave;
     SwTblToTxtSaves* pBoxSaves;
@@ -248,7 +248,7 @@ class SwUndoTblNumFmt : public SwUndo
 {
     SfxItemSet *pBoxSet;
     SwHistory* pHistory;
-    String aStr, aNewFml;
+    OUString aStr, aNewFml;
 
     sal_uLong nFmtIdx, nNewFmtIdx;
     double fNum, fNewNum;
@@ -342,7 +342,7 @@ public:
 
 class SwUndoMergeTbl : public SwUndo
 {
-    String aName;
+    OUString aName;
     sal_uLong nTblNode;
     _SaveTable* pSavTbl, *pSavHdl;
     SwHistory* pHistory;
diff --git a/sw/source/core/undo/unattr.cxx b/sw/source/core/undo/unattr.cxx
index 8a194d009b57..365c871d756c 100644
--- a/sw/source/core/undo/unattr.cxx
+++ b/sw/source/core/undo/unattr.cxx
@@ -1052,7 +1052,7 @@ void SwUndoMoveLeftMargin::RepeatImpl(::sw::RepeatContext & rContext)
 }
 
 SwUndoChangeFootNote::SwUndoChangeFootNote(
-            const SwPaM& rRange, const String& rTxt,
+            const SwPaM& rRange, const OUString& rTxt,
             sal_uInt16 nNum, bool bIsEndNote )
     : SwUndo( UNDO_CHGFTN ), SwUndRng( rRange )
     , m_pHistory( new SwHistory() )
diff --git a/sw/source/core/undo/undel.cxx b/sw/source/core/undo/undel.cxx
index 766ed61c72f1..ce0988c28842 100644
--- a/sw/source/core/undo/undel.cxx
+++ b/sw/source/core/undo/undel.cxx
@@ -361,13 +361,13 @@ sal_Bool SwUndoDelete::SaveCntnt( const SwPosition* pStt, const SwPosition* pEnd
 
         // delete now also the text (all attribute changes are added to
         // UNDO history)
-        pSttStr = new String( pSttTxtNd->GetTxt().copy(nSttCntnt, nLen));
+        pSttStr = new OUString( pSttTxtNd->GetTxt().copy(nSttCntnt, nLen));
         pSttTxtNd->EraseText( pStt->nContent, nLen );
         if( pSttTxtNd->GetpSwpHints() )
             pSttTxtNd->GetpSwpHints()->DeRegister();
 
         // METADATA: store
-        bool emptied( pSttStr->Len() && !pSttTxtNd->Len() );
+        bool emptied( !pSttStr->isEmpty() && !pSttTxtNd->Len() );
         if (!bOneNode || emptied) // merging may overwrite xmlids...
         {
             m_pMetadataUndoStart = (emptied)
@@ -396,14 +396,14 @@ sal_Bool SwUndoDelete::SaveCntnt( const SwPosition* pStt, const SwPosition* pEnd
 
         // delete now also the text (all attribute changes are added to
         // UNDO history)
-        pEndStr = new String( pEndTxtNd->GetTxt().copy( 0,
+        pEndStr = new OUString( pEndTxtNd->GetTxt().copy( 0,
                                     pEnd->nContent.GetIndex() ));
         pEndTxtNd->EraseText( aEndIdx, pEnd->nContent.GetIndex() );
         if( pEndTxtNd->GetpSwpHints() )
             pEndTxtNd->GetpSwpHints()->DeRegister();
 
         // METADATA: store
-        bool emptied( pEndStr->Len() && !pEndTxtNd->Len() );
+        bool emptied = !pEndStr->isEmpty() && !pEndTxtNd->Len();
 
         m_pMetadataUndoEnd = (emptied)
             ? pEndTxtNd->CreateUndoForDelete()
@@ -420,7 +420,7 @@ sal_Bool SwUndoDelete::SaveCntnt( const SwPosition* pStt, const SwPosition* pEnd
 sal_Bool SwUndoDelete::CanGrouping( SwDoc* pDoc, const SwPaM& rDelPam )
 {
     // Is Undo greater than one Node (that is Start and EndString)?
-    if( pSttStr ? !pSttStr->Len() || pEndStr : sal_True )
+    if( pSttStr ? pSttStr->isEmpty() || pEndStr : sal_True )
         return sal_False;
 
     // only the deletion of single char's can be condensed
@@ -456,7 +456,7 @@ sal_Bool SwUndoDelete::CanGrouping( SwDoc* pDoc, const SwPaM& rDelPam )
     SwTxtNode * pDelTxtNd = pStt->nNode.GetNode().GetTxtNode();
     if( !pDelTxtNd ) return sal_False;
 
-    xub_StrLen nUChrPos = bBackSp ? 0 : pSttStr->Len()-1;
+    xub_StrLen nUChrPos = bBackSp ? 0 : pSttStr->getLength()-1;
     sal_Unicode cDelChar = pDelTxtNd->GetTxt()[ pStt->nContent.GetIndex() ];
     CharClass& rCC = GetAppCharClass();
     if( ( CH_TXTATR_BREAKWORD == cDelChar || CH_TXTATR_INWORD == cDelChar ) ||
@@ -487,7 +487,7 @@ sal_Bool SwUndoDelete::CanGrouping( SwDoc* pDoc, const SwPaM& rDelPam )
         nEndCntnt++;    // Delete: attach char at the end
         nUChrPos++;
     }
-    pSttStr->Insert( cDelChar, nUChrPos );
+    (*pSttStr) = pSttStr->replaceAt( nUChrPos, 0, OUString(cDelChar) );
     pDelTxtNd->EraseText( pStt->nContent, 1 );
 
     bGroup = sal_True;
@@ -595,21 +595,21 @@ static String lcl_DenotedPortion(String rStr, xub_StrLen nStart,
     return aResult;
 }
 
-String DenoteSpecialCharacters(const String & rStr)
+OUString DenoteSpecialCharacters(const OUString & rStr)
 {
-    String aResult;
+    OUString aResult;
 
-    if (rStr.Len() > 0)
+    if (!rStr.isEmpty())
     {
         bool bStart = false;
         xub_StrLen nStart = 0;
         sal_Unicode cLast = 0;
 
-        for (xub_StrLen i = 0; i < rStr.Len(); i++)
+        for (xub_StrLen i = 0; i < rStr.getLength(); i++)
         {
-            if (lcl_IsSpecialCharacter(rStr.GetChar(i)))
+            if (lcl_IsSpecialCharacter(rStr[i]))
             {
-                if (cLast != rStr.GetChar(i))
+                if (cLast != rStr[i])
                     bStart = true;
 
             }
@@ -627,10 +627,10 @@ String DenoteSpecialCharacters(const String & rStr)
                 bStart = false;
             }
 
-            cLast = rStr.GetChar(i);
+            cLast = rStr[i];
         }
 
-        aResult += lcl_DenotedPortion(rStr, nStart, rStr.Len());
+        aResult += lcl_DenotedPortion(rStr, nStart, rStr.getLength());
     }
     else
         aResult = SwRewriter::GetPlaceHolder(UndoArg2);
@@ -644,7 +644,7 @@ SwRewriter SwUndoDelete::GetRewriter() const
 
     if (nNode != 0)
     {
-        if (sTableName.Len() > 0)
+        if (!sTableName.isEmpty())
         {
 
             SwRewriter aRewriter;
@@ -662,14 +662,14 @@ SwRewriter SwUndoDelete::GetRewriter() const
     {
         String aStr;
 
-        if (pSttStr != NULL && pEndStr != NULL && pSttStr->Len() == 0 &&
-            pEndStr->Len() == 0)
+        if (pSttStr != NULL && pEndStr != NULL && pSttStr->isEmpty() &&
+            pEndStr->isEmpty())
         {
             aStr = SW_RESSTR(STR_PARAGRAPH_UNDO);
         }
         else
         {
-            String * pStr = NULL;
+            OUString * pStr = NULL;
             if (pSttStr != NULL)
                 pStr = pSttStr;
             else if (pEndStr != NULL)
@@ -788,7 +788,7 @@ void SwUndoDelete::UndoImpl(::sw::UndoRedoContext & rContext)
             {
                 OUString const ins( pTxtNd->InsertText(*pEndStr, aPos.nContent,
                         IDocumentContentOperations::INS_NOHINTEXPAND) );
-                assert(ins.getLength() == pEndStr->Len()); // must succeed
+                assert(ins.getLength() == pEndStr->getLength()); // must succeed
                 (void) ins;
                 // METADATA: restore
                 pTxtNd->RestoreMetadata(m_pMetadataUndoEnd);
@@ -883,7 +883,7 @@ void SwUndoDelete::UndoImpl(::sw::UndoRedoContext & rContext)
                 aPos.nContent.Assign( pTxtNd, nSttCntnt );
                 OUString const ins( pTxtNd->InsertText(*pSttStr, aPos.nContent,
                         IDocumentContentOperations::INS_NOHINTEXPAND) );
-                assert(ins.getLength() == pSttStr->Len()); // must succeed
+                assert(ins.getLength() == pSttStr->getLength()); // must succeed
                 (void) ins;
                 // METADATA: restore
                 pTxtNd->RestoreMetadata(m_pMetadataUndoStart);
@@ -1074,7 +1074,7 @@ void SwUndoDelete::RepeatImpl(::sw::RepeatContext & rContext)
 }
 
 
-void SwUndoDelete::SetTableName(const String & rName)
+void SwUndoDelete::SetTableName(const OUString & rName)
 {
     sTableName = rName;
 }
diff --git a/sw/source/core/undo/undobj.cxx b/sw/source/core/undo/undobj.cxx
index 19ddb0975478..510fff184b6a 100644
--- a/sw/source/core/undo/undobj.cxx
+++ b/sw/source/core/undo/undobj.cxx
@@ -1093,17 +1093,17 @@ sal_Bool SwUndo::CanRedlineGroup( SwRedlineSaveDatas& rCurr,
 }
 
 // #111827#
-String ShortenString(const String & rStr, xub_StrLen nLength, const String & rFillStr)
+OUString ShortenString(const OUString & rStr, xub_StrLen nLength, const OUString & rFillStr)
 {
-    assert(nLength - rFillStr.Len() >= 2);
+    assert(nLength - rFillStr.getLength() >= 2);
 
-    String aResult;
+    OUString aResult;
 
-    if (rStr.Len() <= nLength)
+    if (rStr.getLength() <= nLength)
         aResult = rStr;
     else
     {
-        long nTmpLength = nLength - rFillStr.Len();
+        long nTmpLength = nLength - rFillStr.getLength();
         if ( nTmpLength < 2 )
             nTmpLength = 2;
 
@@ -1112,9 +1112,9 @@ String ShortenString(const String & rStr, xub_StrLen nLength, const String & rFi
         const xub_StrLen nFrontLen = nLength - nLength / 2;
         const xub_StrLen nBackLen = nLength - nFrontLen;
 
-        aResult += rStr.Copy(0, nFrontLen);
+        aResult += rStr.copy(0, nFrontLen);
         aResult += rFillStr;
-        aResult += rStr.Copy(rStr.Len() - nBackLen, nBackLen);
+        aResult += rStr.copy(rStr.getLength() - nBackLen, nBackLen);
     }
 
     return aResult;
diff --git a/sw/source/core/undo/unins.cxx b/sw/source/core/undo/unins.cxx
index 3f3a00e83ad2..bc533af108fd 100644
--- a/sw/source/core/undo/unins.cxx
+++ b/sw/source/core/undo/unins.cxx
@@ -62,9 +62,9 @@ using namespace ::com::sun::star;
 
 // INSERT
 
-String * SwUndoInsert::GetTxtFromDoc() const
+OUString * SwUndoInsert::GetTxtFromDoc() const
 {
-    String * pResult = NULL;
+    OUString * pResult = NULL;
 
     SwNodeIndex aNd( pDoc->GetNodes(), nNode);
     SwCntntNode* pCNd = aNd.GetNode().GetCntntNode();
@@ -85,7 +85,7 @@ String * SwUndoInsert::GetTxtFromDoc() const
             nStart = 0;
         }
 
-        pResult = new String(sTxt.copy(nStart, nLength));
+        pResult = new OUString(sTxt.copy(nStart, nLength));
     }
 
     return pResult;
@@ -145,7 +145,7 @@ sal_Bool SwUndoInsert::CanGrouping( sal_Unicode cIns )
         nCntnt++;
 
         if (pUndoTxt)
-            pUndoTxt->Insert(cIns);
+            (*pUndoTxt) += OUString(cIns);
 
         return sal_True;
     }
@@ -262,7 +262,7 @@ void SwUndoInsert::UndoImpl(::sw::UndoRedoContext & rContext)
                         aPaM.GetMark()->nContent.GetIndex());
                 }
                 RemoveIdxFromRange( aPaM, sal_False );
-                pTxt = new String( pTxtNode->GetTxt().copy(nCntnt-nLen, nLen) );
+                pTxt = new OUString( pTxtNode->GetTxt().copy(nCntnt-nLen, nLen) );
                 pTxtNode->EraseText( aPaM.GetPoint()->nContent, nLen );
 
                 // Undo deletes fieldmarks in two step: first the end then the start position.
@@ -364,7 +364,7 @@ void SwUndoInsert::RedoImpl(::sw::UndoRedoContext & rContext)
                 OUString const ins(
                     pTxtNode->InsertText( *pTxt, pPam->GetMark()->nContent,
                     m_nInsertFlags) );
-                assert(ins.getLength() == pTxt->Len()); // must succeed
+                assert(ins.getLength() == pTxt->getLength()); // must succeed
                 DELETEZ( pTxt );
                 if (m_bWithRsid) // re-insert RSID
                 {
@@ -478,7 +478,7 @@ void SwUndoInsert::RepeatImpl(::sw::RepeatContext & rContext)
 SwRewriter SwUndoInsert::GetRewriter() const
 {
     SwRewriter aResult;
-    String * pStr = NULL;
+    OUString * pStr = NULL;
     bool bDone = false;
 
     if (pTxt)
@@ -897,12 +897,12 @@ void SwUndoReRead::SaveGraphicData( const SwGrfNode& rGrfNd )
 
 
 SwUndoInsertLabel::SwUndoInsertLabel( const SwLabelType eTyp,
-                                      const String &rTxt,
-                                      const String& rSeparator,
-                                      const String& rNumberSeparator,
+                                      const OUString &rTxt,
+                                      const OUString& rSeparator,
+                                      const OUString& rNumberSeparator,
                                       const sal_Bool bBef,
                                       const sal_uInt16 nInitId,
-                                      const String& rCharacterStyle,
+                                      const OUString& rCharacterStyle,
                                       const sal_Bool bCpyBorder )
     : SwUndo( UNDO_INSERTLABEL ),
       sText( rTxt ),
diff --git a/sw/source/core/undo/unnum.cxx b/sw/source/core/undo/unnum.cxx
index 32fe562ba425..21a7caf6dc9c 100644
--- a/sw/source/core/undo/unnum.cxx
+++ b/sw/source/core/undo/unnum.cxx
@@ -45,7 +45,7 @@ SwUndoInsNum::SwUndoInsNum( const SwPaM& rPam, const SwNumRule& rRule )
 }
 
 SwUndoInsNum::SwUndoInsNum( const SwPosition& rPos, const SwNumRule& rRule,
-                            const String& rReplaceRule )
+                            const OUString& rReplaceRule )
     : SwUndo( UNDO_INSNUM ),
     aNumRule( rRule ), pHistory( 0 ),
     nSttSet( ULONG_MAX ), pOldNumRule( 0 ),
@@ -117,7 +117,7 @@ void SwUndoInsNum::RedoImpl(::sw::UndoRedoContext & rContext)
     else if( pHistory )
     {
         SwPaM & rPam( AddUndoRedoPaM(rContext) );
-        if( sReplaceRule.Len() )
+        if( !sReplaceRule.isEmpty() )
         {
             rDoc.ReplaceNumRule(*rPam.GetPoint(),
                                 sReplaceRule, aNumRule.GetName() );
@@ -141,7 +141,7 @@ void SwUndoInsNum::RepeatImpl(::sw::RepeatContext & rContext)
     SwDoc & rDoc(rContext.GetDoc());
     if( nSttNode )
     {
-        if( !sReplaceRule.Len() )
+        if( sReplaceRule.isEmpty() )
         {
             // #i42921# - adapt to changed signature
             rDoc.SetNumRule(rContext.GetRepeatPaM(), aNumRule, false);
diff --git a/sw/source/core/undo/unovwr.cxx b/sw/source/core/undo/unovwr.cxx
index 6a2fc8acc197..2c06cd4777d6 100644
--- a/sw/source/core/undo/unovwr.cxx
+++ b/sw/source/core/undo/unovwr.cxx
@@ -63,7 +63,7 @@ SwUndoOverwrite::SwUndoOverwrite( SwDoc* pDoc, SwPosition& rPos,
     xub_StrLen nTxtNdLen = pTxtNd->GetTxt().getLength();
     if( nSttCntnt < nTxtNdLen )     // no pure insert?
     {
-        aDelStr.Insert( pTxtNd->GetTxt()[nSttCntnt] );
+        aDelStr += OUString( pTxtNd->GetTxt()[nSttCntnt] );
         if( !pHistory )
             pHistory = new SwHistory;
         SwRegHistory aRHst( *pTxtNd, pHistory );
@@ -78,7 +78,7 @@ SwUndoOverwrite::SwUndoOverwrite( SwDoc* pDoc, SwPosition& rPos,
 
     pTxtNd->InsertText( OUString(cIns), rPos.nContent,
             IDocumentContentOperations::INS_EMPTYEXPAND );
-    aInsStr.Insert( cIns );
+    aInsStr += OUString( cIns );
 
     if( !bInsChar )
     {
@@ -101,15 +101,15 @@ sal_Bool SwUndoOverwrite::CanGrouping( SwDoc* pDoc, SwPosition& rPos,
 // What is with only inserted characters?
 
     // Only deletion of single chars can be combined.
-    if( rPos.nNode != nSttNode || !aInsStr.Len()  ||
-        ( !bGroup && aInsStr.Len() != 1 ))
+    if( rPos.nNode != nSttNode || aInsStr.isEmpty()  ||
+        ( !bGroup && aInsStr.getLength() != 1 ))
         return sal_False;
 
     // Is the node a TextNode at all?
     SwTxtNode * pDelTxtNd = rPos.nNode.GetNode().GetTxtNode();
     if( !pDelTxtNd ||
         (pDelTxtNd->GetTxt().getLength() != rPos.nContent.GetIndex() &&
-            rPos.nContent.GetIndex() != ( nSttCntnt + aInsStr.Len() )))
+            rPos.nContent.GetIndex() != ( nSttCntnt + aInsStr.getLength() )))
         return sal_False;
 
     CharClass& rCC = GetAppCharClass();
@@ -117,7 +117,7 @@ sal_Bool SwUndoOverwrite::CanGrouping( SwDoc* pDoc, SwPosition& rPos,
     // ask the char that should be inserted
     if (( CH_TXTATR_BREAKWORD == cIns || CH_TXTATR_INWORD == cIns ) ||
         rCC.isLetterNumeric( OUString( cIns ), 0 ) !=
-        rCC.isLetterNumeric( aInsStr, aInsStr.Len()-1 ) )
+        rCC.isLetterNumeric( aInsStr, aInsStr.getLength()-1 ) )
         return sal_False;
 
     {
@@ -144,7 +144,7 @@ sal_Bool SwUndoOverwrite::CanGrouping( SwDoc* pDoc, SwPosition& rPos,
     {
         if (rPos.nContent.GetIndex() < pDelTxtNd->GetTxt().getLength())
         {
-            aDelStr.Insert(pDelTxtNd->GetTxt()[rPos.nContent.GetIndex()]);
+            aDelStr += OUString( pDelTxtNd->GetTxt()[rPos.nContent.GetIndex()] );
             rPos.nContent++;
         }
         else
@@ -158,7 +158,7 @@ sal_Bool SwUndoOverwrite::CanGrouping( SwDoc* pDoc, SwPosition& rPos,
             IDocumentContentOperations::INS_EMPTYEXPAND) );
     assert(ins.getLength() == 1); // check in SwDoc::Overwrite => cannot fail
     (void) ins;
-    aInsStr.Insert( cIns );
+    aInsStr += OUString( cIns );
 
     if( !bInsChar )
     {
@@ -186,29 +186,29 @@ void SwUndoOverwrite::UndoImpl(::sw::UndoRedoContext & rContext)
     SwAutoCorrExceptWord* pACEWord = pDoc->GetAutoCorrExceptWord();
     if( pACEWord )
     {
-        if( 1 == aInsStr.Len() && 1 == aDelStr.Len() )
-            pACEWord->CheckChar( *pAktPam->GetPoint(), aDelStr.GetChar( 0 ) );
+        if( 1 == aInsStr.getLength() && 1 == aDelStr.getLength() )
+            pACEWord->CheckChar( *pAktPam->GetPoint(), aDelStr[0] );
         pDoc->SetAutoCorrExceptWord( 0 );
     }
 
     // If there was not only a overwrite but also an insert, delete the surplus
-    if( aInsStr.Len() > aDelStr.Len() )
+    if( aInsStr.getLength() > aDelStr.getLength() )
     {
-        rIdx += aDelStr.Len();
-        pTxtNd->EraseText( rIdx, aInsStr.Len() - aDelStr.Len() );
+        rIdx += aDelStr.getLength();
+        pTxtNd->EraseText( rIdx, aInsStr.getLength() - aDelStr.getLength() );
         rIdx = nSttCntnt;
     }
 
-    if( aDelStr.Len() )
+    if( !aDelStr.isEmpty() )
     {
         bool bOldExpFlg = pTxtNd->IsIgnoreDontExpand();
         pTxtNd->SetIgnoreDontExpand( true );
 
         ++rIdx;
-        for( xub_StrLen n = 0; n < aDelStr.Len(); n++  )
+        for( xub_StrLen n = 0; n < aDelStr.getLength(); n++  )
         {
             // do it individually, to keep the attributes!
-            OUString aTmpStr(aDelStr.GetChar(n));
+            OUString aTmpStr(aDelStr[n]);
             OUString const ins( pTxtNd->InsertText(aTmpStr, rIdx) );
             assert(ins.getLength() == 1); // cannot fail
         (void) ins;
@@ -240,17 +240,17 @@ void SwUndoOverwrite::UndoImpl(::sw::UndoRedoContext & rContext)
 void SwUndoOverwrite::RepeatImpl(::sw::RepeatContext & rContext)
 {
     SwPaM *const pAktPam = & rContext.GetRepeatPaM();
-    if( !aInsStr.Len() || pAktPam->HasMark() )
+    if( aInsStr.isEmpty() || pAktPam->HasMark() )
         return;
 
     SwDoc & rDoc = rContext.GetDoc();
 
     {
         ::sw::GroupUndoGuard const undoGuard(rDoc.GetIDocumentUndoRedo());
-        rDoc.Overwrite(*pAktPam, OUString(aInsStr.GetChar(0)));
+        rDoc.Overwrite(*pAktPam, OUString(aInsStr[0]));
     }
-    for( xub_StrLen n = 1; n < aInsStr.Len(); ++n )
-        rDoc.Overwrite( *pAktPam, OUString(aInsStr.GetChar(n)) );
+    for( xub_StrLen n = 1; n < aInsStr.getLength(); ++n )
+        rDoc.Overwrite( *pAktPam, OUString(aInsStr[n]) );
 }
 
 void SwUndoOverwrite::RedoImpl(::sw::UndoRedoContext & rContext)
@@ -268,28 +268,28 @@ void SwUndoOverwrite::RedoImpl(::sw::UndoRedoContext & rContext)
     {
         rIdx.Assign( pTxtNd, nSttCntnt );
         pAktPam->SetMark();
-        pAktPam->GetMark()->nContent += aInsStr.Len();
+        pAktPam->GetMark()->nContent += aInsStr.getLength();
         pDoc->DeleteRedline( *pAktPam, false, USHRT_MAX );
         pAktPam->DeleteMark();
     }
-    rIdx.Assign( pTxtNd, aDelStr.Len() ? nSttCntnt+1 : nSttCntnt );
+    rIdx.Assign( pTxtNd, !aDelStr.isEmpty() ? nSttCntnt+1 : nSttCntnt );
 
     bool bOldExpFlg = pTxtNd->IsIgnoreDontExpand();
     pTxtNd->SetIgnoreDontExpand( true );
 
-    for( xub_StrLen n = 0; n < aInsStr.Len(); n++  )
+    for( xub_StrLen n = 0; n < aInsStr.getLength(); n++  )
     {
         // do it individually, to keep the attributes!
         OUString const ins(
-                pTxtNd->InsertText( OUString(aInsStr.GetChar(n)), rIdx,
+                pTxtNd->InsertText( OUString(aInsStr[n]), rIdx,
                 IDocumentContentOperations::INS_EMPTYEXPAND) );
         assert(ins.getLength() == 1); // cannot fail
         (void) ins;
-        if( n < aDelStr.Len() )
+        if( n < aDelStr.getLength() )
         {
             rIdx -= 2;
             pTxtNd->EraseText( rIdx, 1 );
-            rIdx += n+1 < aDelStr.Len() ? 2 : 1;
+            rIdx += n+1 < aDelStr.getLength() ? 2 : 1;
         }
     }
     pTxtNd->SetIgnoreDontExpand( bOldExpFlg );
diff --git a/sw/source/core/undo/unsort.cxx b/sw/source/core/undo/unsort.cxx
index 59634e2c2ed9..d99e2feac04f 100644
--- a/sw/source/core/undo/unsort.cxx
+++ b/sw/source/core/undo/unsort.cxx
@@ -245,7 +245,7 @@ void SwUndoSort::RepeatImpl(::sw::RepeatContext & rContext)
     }
 }
 
-void SwUndoSort::Insert( const String& rOrgPos, const String& rNewPos)
+void SwUndoSort::Insert( const OUString& rOrgPos, const OUString& rNewPos)
 {
     SwSortUndoElement* pEle = new SwSortUndoElement(rOrgPos, rNewPos);
     aSortList.push_back( pEle );
diff --git a/sw/source/core/undo/untbl.cxx b/sw/source/core/undo/untbl.cxx
index 4ed6fa724a0e..f15e6290532c 100644
--- a/sw/source/core/undo/untbl.cxx
+++ b/sw/source/core/undo/untbl.cxx
@@ -224,7 +224,7 @@ SwUndoInsTbl::SwUndoInsTbl( const SwPosition& rPos, sal_uInt16 nCl, sal_uInt16 n
                             sal_uInt16 nAdj, const SwInsertTableOptions& rInsTblOpts,
                             const SwTableAutoFmt* pTAFmt,
                             const std::vector<sal_uInt16> *pColArr,
-                            const String & rName)
+                            const OUString & rName)
     : SwUndo( UNDO_INSTABLE ),
     aInsTblOpts( rInsTblOpts ), pDDEFldType( 0 ), pColWidth( 0 ), pRedlData( 0 ), pAutoFmt( 0 ),
     nSttNode( rPos.nNode.GetIndex() ), nRows( nRw ), nCols( nCl ), nAdjust( nAdj )
@@ -2220,7 +2220,7 @@ void SwUndoTblNumFmt::UndoImpl(::sw::UndoRedoContext & rContext)
     if( pTxtNd->HasSwAttrSet() )
         pTxtNd->ResetAllAttr();
 
-    if( pTxtNd->GetpSwpHints() && aStr.Len() )
+    if( pTxtNd->GetpSwpHints() && !aStr.isEmpty() )
         pTxtNd->ClearSwpHintsArr( true );
 
     // ChgTextToNum(..) only acts when the strings are different. We need to do
@@ -2230,7 +2230,7 @@ void SwUndoTblNumFmt::UndoImpl(::sw::UndoRedoContext & rContext)
         rDoc.DeleteRedline( *( pBox->GetSttNd() ), false, USHRT_MAX );
 
         SwIndex aIdx( pTxtNd, 0 );
-        if( aStr.Len() )
+        if( !aStr.isEmpty() )
         {
             pTxtNd->EraseText( aIdx );
             pTxtNd->InsertText( aStr, aIdx,