diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/IXLColumn.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/IXLColumn.cs
index e4b8e69..a7dd91f 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/IXLColumn.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/IXLColumn.cs
@@ -21,9 +21,12 @@
         void Unhide();
         Boolean IsHidden { get; }
         Int32 OutlineLevel { get; set; }
-        void Group(Boolean collapse = false);
-        void Group(Int32 outlineLevel, Boolean collapse = false);
-        void Ungroup(Boolean fromAll = false);
+        void Group();
+        void Group(Boolean collapse);
+        void Group(Int32 outlineLevel);
+        void Group(Int32 outlineLevel, Boolean collapse);
+        void Ungroup();
+        void Ungroup(Boolean fromAll);
         void Collapse();
         void Expand();
 
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/IXLColumns.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/IXLColumns.cs
index 480a753..380ee97 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/IXLColumns.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/IXLColumns.cs
@@ -12,8 +12,11 @@
         void AdjustToContents();
         void Hide();
         void Unhide();
-        void Group(Boolean collapse = false);
+        void Group();
+        void Group(Boolean collapse);
+        void Group(Int32 outlineLevel);
         void Group(Int32 outlineLevel, Boolean collapse = false);
+        void Ungroup();
         void Ungroup(Boolean fromAll = false);
         void Collapse();
         void Expand();
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumn.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumn.cs
index abf5885..3bf8ec8 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumn.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumn.cs
@@ -307,20 +307,31 @@
                 }
             }
         }
-
-        public void Group(Boolean collapse = false)
+        public void Group()
+        {
+            Group(false);
+        }
+        public void Group(Boolean collapse)
         {
             if (OutlineLevel < 8)
                 OutlineLevel += 1;
 
             Collapsed = collapse;
         }
-        public void Group(Int32 outlineLevel, Boolean collapse = false)
+        public void Group(Int32 outlineLevel)
+        {
+            Group(outlineLevel, false);
+        }
+        public void Group(Int32 outlineLevel, Boolean collapse)
         {
             OutlineLevel = outlineLevel;
             Collapsed = collapse;
         }
-        public void Ungroup(Boolean ungroupFromAll = false)
+        public void Ungroup()
+        {
+            Ungroup(false);
+        }
+        public void Ungroup(Boolean ungroupFromAll)
         {
             if (ungroupFromAll)
             {
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumns.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumns.cs
index 0d966f3..1b15d19 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumns.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumns.cs
@@ -156,16 +156,27 @@
         {
             columns.ForEach(c => c.Unhide());
         }
-
-        public void Group(Boolean collapse = false)
+        public void Group()
+        {
+            Group(false);
+        }
+        public void Group(Int32 outlineLevel)
+        {
+            Group(outlineLevel, false);
+        }
+        public void Ungroup()
+        {
+            Ungroup(false);
+        }
+        public void Group(Boolean collapse)
         {
             columns.ForEach(c => c.Group(collapse));
         }
-        public void Group(Int32 outlineLevel, Boolean collapse = false)
+        public void Group(Int32 outlineLevel, Boolean collapse)
         {
             columns.ForEach(c => c.Group(outlineLevel, collapse));
         }
-        public void Ungroup(Boolean ungroupFromAll = false)
+        public void Ungroup(Boolean ungroupFromAll)
         {
             columns.ForEach(c => c.Ungroup(ungroupFromAll));
         }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRanges.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRanges.cs
index c081849..24233aa 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRanges.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRanges.cs
@@ -9,9 +9,12 @@
     {
         IXLNamedRange NamedRange(String rangeName);
         IXLNamedRange NamedRange(Int32 rangeIndex);
-        IXLNamedRange Add(String rangeName, String rangeAddress, String comment = null);
-        IXLNamedRange Add(String rangeName, IXLRange range, String comment = null);
-        IXLNamedRange Add(String rangeName, IXLRanges ranges, String comment = null);
+        IXLNamedRange Add(String rangeName, String rangeAddress);
+        IXLNamedRange Add(String rangeName, IXLRange range);
+        IXLNamedRange Add(String rangeName, IXLRanges ranges);
+        IXLNamedRange Add(String rangeName, String rangeAddress, String comment);
+        IXLNamedRange Add(String rangeName, IXLRange range, String comment);
+        IXLNamedRange Add(String rangeName, IXLRanges ranges, String comment);
         void Delete(String rangeName);
         void Delete(Int32 rangeIndex);
         void DeleteAll();
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs
index 2e49830..c3b53da 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs
@@ -27,21 +27,31 @@
             return namedRanges.ElementAt(rangeIndex).Value;
         }
 
-        public IXLNamedRange Add(String rangeName, String rangeAddress, String comment = null)
+        public IXLNamedRange Add(String rangeName, String rangeAddress)
+        {
+            return Add(rangeName, rangeAddress, null);
+        }
+        public IXLNamedRange Add(String rangeName, IXLRange range)
+        {
+            return Add(rangeName, range, null);
+        }
+        public IXLNamedRange Add(String rangeName, IXLRanges ranges)
+        {
+            return Add(rangeName, ranges, null);
+        }
+        public IXLNamedRange Add(String rangeName, String rangeAddress, String comment )
         {
             var namedRange = new XLNamedRange(this, rangeName, rangeAddress, comment);
             namedRanges.Add(rangeName, namedRange);
             return namedRange;
         }
-
-        public IXLNamedRange Add(String rangeName, IXLRange range, String comment = null)
+        public IXLNamedRange Add(String rangeName, IXLRange range, String comment)
         {
             var ranges = new XLRanges(((XLRange)range).Worksheet.Internals.Workbook, range.Style);
             ranges.Add(range);
             return Add(rangeName, ranges, comment);
         }
-
-        public IXLNamedRange Add(String rangeName, IXLRanges ranges, String comment = null)
+        public IXLNamedRange Add(String rangeName, IXLRanges ranges, String comment)
         {
             var namedRange = new XLNamedRange(this, rangeName, ranges, comment);
             namedRanges.Add(rangeName, namedRange);
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/PageSetup/IXLHFItem.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/PageSetup/IXLHFItem.cs
index 9b3dac9..4beabc9 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/PageSetup/IXLHFItem.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/PageSetup/IXLHFItem.cs
@@ -17,8 +17,12 @@
     public interface IXLHFItem
     {
         String GetText(XLHFOccurrence occurrence);
-        void AddText(String text, XLHFOccurrence occurrence = XLHFOccurrence.AllPages, IXLFont xlFont = null);
-        void AddText(XLHFPredefinedText predefinedText, XLHFOccurrence occurrence = XLHFOccurrence.AllPages, IXLFont xlFont = null);
+        void AddText(String text);
+        void AddText(XLHFPredefinedText predefinedText);
+        void AddText(String text, XLHFOccurrence occurrence);
+        void AddText(XLHFPredefinedText predefinedText, XLHFOccurrence occurrence);
+        void AddText(String text, XLHFOccurrence occurrence, IXLFont xlFont);
+        void AddText(XLHFPredefinedText predefinedText, XLHFOccurrence occurrence, IXLFont xlFont);
         void Clear(XLHFOccurrence occurrence = XLHFOccurrence.AllPages);
     }
 }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/PageSetup/XLHFItem.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/PageSetup/XLHFItem.cs
index d5cc0bc..f84aaae 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/PageSetup/XLHFItem.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/PageSetup/XLHFItem.cs
@@ -16,7 +16,24 @@
                 return String.Empty;
         }
 
-        public void AddText(String text, XLHFOccurrence occurrence = XLHFOccurrence.AllPages, IXLFont xlFont = null)
+        public void AddText(String text)
+        {
+            AddText(text, XLHFOccurrence.AllPages);
+        }
+        public void AddText(XLHFPredefinedText predefinedText)
+        {
+            AddText(predefinedText, XLHFOccurrence.AllPages);
+        }
+        public void AddText(String text, XLHFOccurrence occurrence)
+        {
+            AddText(text, occurrence, null);
+        }
+        public void AddText(XLHFPredefinedText predefinedText, XLHFOccurrence occurrence)
+        {
+            AddText(predefinedText, occurrence, null);
+        }
+
+        public void AddText(String text, XLHFOccurrence occurrence, IXLFont xlFont)
         {
             if (text.Length > 0)
             {
@@ -47,7 +64,7 @@
             }
         }
 
-        public void AddText(XLHFPredefinedText predefinedText, XLHFOccurrence occurrence = XLHFOccurrence.AllPages, IXLFont xlFont = null)
+        public void AddText(XLHFPredefinedText predefinedText, XLHFOccurrence occurrence, IXLFont xlFont)
         {
             String hfText;
             switch (predefinedText)
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeBase.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeBase.cs
index 0a2de52..77611b8 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeBase.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeBase.cs
@@ -12,9 +12,11 @@
         IEnumerable<IXLCell> CellsUsed();
         IXLRangeAddress RangeAddress { get; }
         IXLCell FirstCell();
-        IXLCell FirstCellUsed(Boolean ignoreStyle = true);
+        IXLCell FirstCellUsed();
+        IXLCell FirstCellUsed(Boolean ignoreStyle);
         IXLCell LastCell();
-        IXLCell LastCellUsed(Boolean ignoreStyle = true);
+        IXLCell LastCellUsed();
+        IXLCell LastCellUsed(Boolean ignoreStyle);
         IXLRange Range(IXLRangeAddress rangeAddress);
         IXLRange Range(string rangeAddress);
         IXLRange Range(string firstCellAddress, string lastCellAddress);
@@ -25,6 +27,8 @@
         IXLRange Merge();
         IXLRange AsRange();
         Boolean ContainsRange(String rangeAddress);
-        IXLRange AddToNamed(String rangeName, XLScope scope = XLScope.Workbook, String comment = null);
+        IXLRange AddToNamed(String rangeName);
+        IXLRange AddToNamed(String rangeName, XLScope scope);
+        IXLRange AddToNamed(String rangeName, XLScope scope, String comment);
     }
 }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeColumn.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeColumn.cs
index 164046c..8d0c891 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeColumn.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeColumn.cs
@@ -20,7 +20,8 @@
         void InsertRowsAbove(int numberOfRows);
         void InsertRowsBelow(int numberOfRows);
 
-        void Delete(XLShiftDeletedCells shiftDeleteCells = XLShiftDeletedCells.ShiftCellsLeft);
+        void Delete();
+        void Delete(XLShiftDeletedCells shiftDeleteCells);
         void Clear();
         String FormulaA1 { set; }
         String FormulaR1C1 { set; }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeRow.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeRow.cs
index 338a4ea..3afec0e 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeRow.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeRow.cs
@@ -22,7 +22,8 @@
         void InsertRowsAbove(int numberOfRows);
         void InsertRowsBelow(int numberOfRows);
 
-        void Delete(XLShiftDeletedCells shiftDeleteCells = XLShiftDeletedCells.ShiftCellsUp);
+        void Delete();
+        void Delete(XLShiftDeletedCells shiftDeleteCells);
         void Clear();
         String FormulaA1 { set; }
         String FormulaR1C1 { set; }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs
index 8a6fcb9..b567f17 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs
@@ -24,8 +24,12 @@
         {
             return this.Cell(this.RowCount(), this.ColumnCount());
         }
-
-        public IXLCell FirstCellUsed(Boolean ignoreStyle = true)
+        
+        public IXLCell FirstCellUsed()
+        {
+            return FirstCellUsed(true);
+        }
+        public IXLCell FirstCellUsed(Boolean ignoreStyle)
         {
             var cellsUsed = CellsUsed();
             if (ignoreStyle)
@@ -43,7 +47,11 @@
             }
         }
 
-        public IXLCell LastCellUsed(Boolean ignoreStyle = true) 
+        public IXLCell LastCellUsed()
+        {
+            return LastCellUsed(true);
+        }
+        public IXLCell LastCellUsed(Boolean ignoreStyle) 
         {
             var cellsUsed = CellsUsed();
             if (ignoreStyle)
@@ -588,7 +596,15 @@
             }
         }
 
-        public IXLRange AddToNamed(String rangeName, XLScope scope = XLScope.Workbook, String comment = null)
+        public IXLRange AddToNamed(String rangeName)
+        {
+            return AddToNamed(rangeName, XLScope.Workbook);
+        }
+        public IXLRange AddToNamed(String rangeName, XLScope scope)
+        {
+            return AddToNamed(rangeName, XLScope.Workbook, null);
+        }
+        public IXLRange AddToNamed(String rangeName, XLScope scope, String comment)
         {
             IXLNamedRanges namedRanges;
             if (scope == XLScope.Workbook)
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeColumn.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeColumn.cs
index f6e060b..4d034d5 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeColumn.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeColumn.cs
@@ -38,11 +38,15 @@
                     && c.Address.RowNumber <= lastRow);
         }
 
-
         public IXLRange Range(int firstRow, int lastRow)
         {
             return Range(firstRow, 1, lastRow, 1);
         }
+
+        public void Delete()
+        {
+            Delete(XLShiftDeletedCells.ShiftCellsLeft);
+        }
     }
 }
 
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeRow.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeRow.cs
index 6fac31a..44db10e 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeRow.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeRow.cs
@@ -51,6 +51,11 @@
         {
             return Range(1, firstColumn, 1, lastColumn);
         }
+
+        public void Delete()
+        {
+            Delete(XLShiftDeletedCells.ShiftCellsUp);
+        }
     }
 }
 
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/IXLRow.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/IXLRow.cs
index 1f9ea2b..8d69e04 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/IXLRow.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/IXLRow.cs
@@ -22,9 +22,12 @@
         void Unhide();
         Boolean IsHidden { get; }
         Int32 OutlineLevel { get; set; }
-        void Group(Boolean collapse = false);
-        void Group(Int32 outlineLevel, Boolean collapse = false);
-        void Ungroup(Boolean fromAll = false);
+        void Group();
+        void Group(Boolean collapse);
+        void Group(Int32 outlineLevel);
+        void Group(Int32 outlineLevel, Boolean collapse);
+        void Ungroup();
+        void Ungroup(Boolean fromAll);
         void Collapse();
         void Expand();
     }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/IXLRows.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/IXLRows.cs
index 6f87a9b..9796f9c 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/IXLRows.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/IXLRows.cs
@@ -12,9 +12,12 @@
         void AdjustToContents();
         void Hide();
         void Unhide();
-        void Group(Boolean collapse = false);
-        void Group(Int32 outlineLevel, Boolean collapse = false);
-        void Ungroup(Boolean fromAll = false);
+        void Group();
+        void Group(Boolean collapse);
+        void Group(Int32 outlineLevel);
+        void Group(Int32 outlineLevel, Boolean collapse);
+        void Ungroup();
+        void Ungroup(Boolean fromAll);
         void Collapse();
         void Expand();
     }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRow.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRow.cs
index 067f460..721e158 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRow.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRow.cs
@@ -313,19 +313,31 @@
             }
         }
 
-        public void Group(Boolean collapse = false)
+        public void Group()
+        {
+            Group(false);
+        }
+        public void Group(Int32 outlineLevel)
+        {
+            Group(outlineLevel, false);
+        }
+        public void Ungroup()
+        {
+            Ungroup(false);
+        }
+        public void Group(Boolean collapse)
         {
             if (OutlineLevel < 8)
                 OutlineLevel += 1;
 
             Collapsed = collapse;
         }
-        public void Group(Int32 outlineLevel, Boolean collapse = false)
+        public void Group(Int32 outlineLevel, Boolean collapse)
         {
             OutlineLevel = outlineLevel;
             Collapsed = collapse;
         }
-        public void Ungroup(Boolean ungroupFromAll = false)
+        public void Ungroup(Boolean ungroupFromAll)
         {
             if (ungroupFromAll)
             {
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRows.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRows.cs
index 23ec0c3..1013836 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRows.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRows.cs
@@ -154,15 +154,27 @@
             rows.ForEach(r => r.Unhide());
         }
 
-        public void Group(Boolean collapse = false)
+        public void Group()
+        {
+            Group(false);
+        }
+        public void Group(Int32 outlineLevel)
+        {
+            Group(outlineLevel, false);
+        }
+        public void Ungroup()
+        {
+            Ungroup(false);
+        }
+        public void Group(Boolean collapse)
         {
             rows.ForEach(r => r.Group(collapse));
         }
-        public void Group(Int32 outlineLevel, Boolean collapse = false)
+        public void Group(Int32 outlineLevel, Boolean collapse)
         {
             rows.ForEach(r => r.Group(outlineLevel, collapse));
         }
-        public void Ungroup(Boolean ungroupFromAll = false)
+        public void Ungroup(Boolean ungroupFromAll)
         {
             rows.ForEach(r => r.Ungroup(ungroupFromAll));
         }