diff --git a/common/plotters/HPGL_plotter.cpp b/common/plotters/HPGL_plotter.cpp
index 14a6d9dbd8..0ace032a49 100644
--- a/common/plotters/HPGL_plotter.cpp
+++ b/common/plotters/HPGL_plotter.cpp
@@ -219,13 +219,13 @@ static const char hpgl_end_polygon_cmd[] = "PM 2; FP; EP;\n";
 static const double PLUsPERDECIMIL = 0.1016;
 
 
-HPGL_PLOTTER::HPGL_PLOTTER()
-        : arcTargetChordLength( 0 ),
-          arcMinChordDegrees( 5.0, DEGREES_T ),
-          m_lineStyle( PLOT_DASH_TYPE::SOLID ),
-          useUserCoords( false ),
-          fitUserCoords( false ),
-          m_current_item( nullptr )
+HPGL_PLOTTER::HPGL_PLOTTER() :
+        m_arcTargetChordLength( 0 ),
+        m_arcMinChordDegrees( 5.0, DEGREES_T ),
+        m_lineStyle( PLOT_DASH_TYPE::SOLID ),
+        m_useUserCoords( false ),
+        m_fitUserCoords( false ),
+        m_current_item( nullptr )
 {
     SetPenSpeed( 40 );      // Default pen speed = 40 cm/s; Pen speed is *always* in cm
     SetPenNumber( 1 );      // Default pen num = 1
@@ -251,17 +251,17 @@ void HPGL_PLOTTER::SetViewport( const VECTOR2I& aOffset, double aIusPerDecimil,
 
 void HPGL_PLOTTER::SetTargetChordLength( double chord_len )
 {
-    arcTargetChordLength = userToDeviceSize( chord_len );
+    m_arcTargetChordLength = userToDeviceSize( chord_len );
 }
 
 
 bool HPGL_PLOTTER::StartPlot()
 {
     wxASSERT( m_outputFile );
-    fprintf( m_outputFile, "IN;VS%d;PU;PA;SP%d;\n", penSpeed, penNumber );
+    fprintf( m_outputFile, "IN;VS%d;PU;PA;SP%d;\n", m_penSpeed, m_penNumber );
 
     // Set HPGL Pen Thickness (in mm) (useful in polygon fill command)
-    double penThicknessMM = userToDeviceSize( penDiameter )/40;
+    double penThicknessMM = userToDeviceSize( m_penDiameter ) / 40;
     fprintf( m_outputFile, "PT %.1f;\n", penThicknessMM );
 
     return true;
@@ -279,9 +279,9 @@ bool HPGL_PLOTTER::EndPlot()
 
     if( m_items.size() > 0 )
     {
-        if( useUserCoords )
+        if( m_useUserCoords )
         {
-            if( fitUserCoords )
+            if( m_fitUserCoords )
             {
                 BOX2D bbox = m_items.front().bbox;
 
@@ -308,7 +308,7 @@ bool HPGL_PLOTTER::EndPlot()
         VECTOR2I       loc          = m_items.begin()->loc_start;
         bool           pen_up       = true;
         PLOT_DASH_TYPE current_dash = PLOT_DASH_TYPE::SOLID;
-        int            current_pen  = penNumber;
+        int            current_pen  = m_penNumber;
 
         for( HPGL_ITEM const& item : m_items )
         {
@@ -326,7 +326,7 @@ bool HPGL_PLOTTER::EndPlot()
             if( item.dashType != current_dash )
             {
                 current_dash = item.dashType;
-                fputs( lineTypeCommand( item.dashType ), m_outputFile );
+                fputs( lineStyleCommand( item.dashType ), m_outputFile );
             }
 
             if( item.pen != current_pen )
@@ -383,7 +383,7 @@ bool HPGL_PLOTTER::EndPlot()
 
 void HPGL_PLOTTER::SetPenDiameter( double diameter )
 {
-    penDiameter = diameter;
+    m_penDiameter = diameter;
 }
 
 
@@ -421,10 +421,10 @@ void HPGL_PLOTTER::Circle( const VECTOR2I& aCenter, int aDiameter, FILL_T aFill,
     SetCurrentLineWidth( aWidth );
 
     double const circumf             = 2.0 * M_PI * radius;
-    double const target_chord_length = arcTargetChordLength;
+    double const target_chord_length = m_arcTargetChordLength;
     EDA_ANGLE    chord_angle         = ANGLE_360 * target_chord_length / circumf;
 
-    chord_angle = std::max( arcMinChordDegrees, std::min( chord_angle, ANGLE_45 ) );
+    chord_angle = std::max( m_arcMinChordDegrees, std::min( chord_angle, ANGLE_45 ) );
 
     if( aFill == FILL_T::FILLED_SHAPE )
     {
@@ -555,7 +555,7 @@ void HPGL_PLOTTER::ThickSegment( const VECTOR2I& start, const VECTOR2I& end,
     wxASSERT( m_outputFile );
 
     // Suppress overlap if pen is too big
-    if( penDiameter >= width )
+    if( m_penDiameter >= width )
     {
         MoveTo( start );
         FinishTo( end );
@@ -575,10 +575,10 @@ void HPGL_PLOTTER::Arc( const VECTOR2I& aCenter, const EDA_ANGLE& aStartAngle,
 
     double const radius_device       = userToDeviceSize( aRadius );
     double const circumf_device      = 2.0 * M_PI * radius_device;
-    double const target_chord_length = arcTargetChordLength;
+    double const target_chord_length = m_arcTargetChordLength;
     EDA_ANGLE    chord_angle         = ANGLE_360 * target_chord_length / circumf_device;
 
-    chord_angle = std::max( arcMinChordDegrees, std::min( chord_angle, ANGLE_45 ) );
+    chord_angle = std::max( m_arcMinChordDegrees, std::min( chord_angle, ANGLE_45 ) );
 
     VECTOR2D  centre_device = userToDeviceCoordinates( aCenter );
     EDA_ANGLE angle;
@@ -640,7 +640,7 @@ void HPGL_PLOTTER::FlashPadOval( const VECTOR2I& aPos, const VECTOR2I& aSize,
     {
         int deltaxy = size.y - size.x;     // distance between centers of the oval
 
-        FlashPadRect( aPos, VECTOR2I( size.x, deltaxy + KiROUND( penDiameter ) ), orient,
+        FlashPadRect( aPos, VECTOR2I( size.x, deltaxy + KiROUND( m_penDiameter ) ), orient,
                       aTraceMode, aData );
 
         VECTOR2I pt( 0, deltaxy / 2 );
@@ -653,7 +653,7 @@ void HPGL_PLOTTER::FlashPadOval( const VECTOR2I& aPos, const VECTOR2I& aSize,
     }
     else    // Plot in outline mode.
     {
-        sketchOval( aPos, size, orient, KiROUND( penDiameter ) );
+        sketchOval( aPos, size, orient, KiROUND( m_penDiameter ) );
     }
 }
 
@@ -669,7 +669,7 @@ void HPGL_PLOTTER::FlashPadCircle( const VECTOR2I& pos, int diametre,
     {
         // if filled mode, the pen diameter is removed from diameter
         // to keep the pad size
-        radius -= KiROUND( penDiameter ) / 2;
+        radius -= KiROUND( m_penDiameter ) / 2;
 
         if( radius < 0 )
             radius = 0;
@@ -715,9 +715,9 @@ void HPGL_PLOTTER::FlashPadRect( const VECTOR2I& aPos, const VECTOR2I& aPadSize,
     {
         // in filled mode, the pen diameter is removed from size
         // to compensate the extra size due to this pen size
-        dx -= KiROUND( penDiameter ) / 2;
+        dx -= KiROUND( m_penDiameter ) / 2;
         dx = std::max( dx, 0);
-        dy -= KiROUND( penDiameter ) / 2;
+        dy -= KiROUND( m_penDiameter ) / 2;
         dy = std::max( dy, 0);
     }
 
@@ -751,9 +751,9 @@ void HPGL_PLOTTER::FlashPadRoundRect( const VECTOR2I& aPadPos, const VECTOR2I& a
     if( aTraceMode == FILLED )
     {
         // In filled mode, the pen diameter is removed from size to keep the pad size.
-        size.x -= KiROUND( penDiameter ) / 2;
+        size.x -= KiROUND( m_penDiameter ) / 2;
         size.x = std::max( size.x, 0);
-        size.y -= KiROUND( penDiameter ) / 2;
+        size.y -= KiROUND( m_penDiameter ) / 2;
         size.y = std::max( size.y, 0);
 
         // keep aCornerRadius to a value < min size x,y < 2:
@@ -853,7 +853,7 @@ bool HPGL_PLOTTER::startOrAppendItem( const VECTOR2D& location, wxString const&
         item.loc_start = location;
         item.loc_end = location;
         item.bbox = BOX2D( location );
-        item.pen = penNumber;
+        item.pen = m_penNumber;
         item.dashType = m_lineStyle;
         item.content = content;
         m_items.push_back( item );
@@ -931,9 +931,9 @@ void HPGL_PLOTTER::sortItems( std::list<HPGL_ITEM>& items )
 }
 
 
-const char* HPGL_PLOTTER::lineTypeCommand( PLOT_DASH_TYPE linetype )
+const char* HPGL_PLOTTER::lineStyleCommand( PLOT_DASH_TYPE aLineStyle )
 {
-    switch( linetype )
+    switch( aLineStyle )
     {
     case PLOT_DASH_TYPE::DASH:       return "LT 2 4 1;";
     case PLOT_DASH_TYPE::DOT:        return "LT 1 1 1;";
diff --git a/include/plotters/plotter_dxf.h b/include/plotters/plotter_dxf.h
index bb1f94993f..f90e285f86 100644
--- a/include/plotters/plotter_dxf.h
+++ b/include/plotters/plotter_dxf.h
@@ -154,19 +154,19 @@ public:
                                       const EDA_ANGLE& aOrient, OUTLINE_MODE aTraceMode,
                                       void* aData ) override;
 
-    virtual void Text( const VECTOR2I&             aPos,
-                       const COLOR4D&              aColor,
-                       const wxString&             aText,
-                       const EDA_ANGLE&            aOrient,
-                       const VECTOR2I&             aSize,
-                       enum GR_TEXT_H_ALIGN_T      aH_justify,
-                       enum GR_TEXT_V_ALIGN_T      aV_justify,
-                       int                         aWidth,
-                       bool                        aItalic,
-                       bool                        aBold,
-                       bool                        aMultilineAllowed = false,
-                       KIFONT::FONT*            aFont = nullptr,
-                       void*                       aData = nullptr ) override;
+    virtual void Text( const VECTOR2I&        aPos,
+                       const COLOR4D&         aColor,
+                       const wxString&        aText,
+                       const EDA_ANGLE&       aOrient,
+                       const VECTOR2I&        aSize,
+                       enum GR_TEXT_H_ALIGN_T aH_justify,
+                       enum GR_TEXT_V_ALIGN_T aV_justify,
+                       int                    aWidth,
+                       bool                   aItalic,
+                       bool                   aBold,
+                       bool                   aMultilineAllowed = false,
+                       KIFONT::FONT*          aFont = nullptr,
+                       void*                  aData = nullptr ) override;
 
 
     /**
diff --git a/include/plotters/plotter_hpgl.h b/include/plotters/plotter_hpgl.h
index c73d878b9d..ad2ec8e068 100644
--- a/include/plotters/plotter_hpgl.h
+++ b/include/plotters/plotter_hpgl.h
@@ -53,10 +53,10 @@ public:
     void SetTargetChordLength( double chord_len );
 
     /// Switch to the user coordinate system
-    void SetUserCoords( bool user_coords ) { useUserCoords = user_coords; }
+    void SetUserCoords( bool user_coords ) { m_useUserCoords = user_coords; }
 
     /// Set whether the user coordinate system is fit to content
-    void SetUserCoordsFit( bool user_coords_fit ) { fitUserCoords = user_coords_fit; }
+    void SetUserCoordsFit( bool user_coords_fit ) { m_fitUserCoords = user_coords_fit; }
 
     /**
      * At the start of the HPGL plot pen speed and number are requested.
@@ -72,7 +72,7 @@ public:
     virtual void SetCurrentLineWidth( int width, void* aData = nullptr ) override
     {
         // This is the truth
-        m_currentPenWidth = userToDeviceSize( penDiameter );
+        m_currentPenWidth = userToDeviceSize( m_penDiameter );
     }
 
     /**
@@ -84,12 +84,12 @@ public:
 
     virtual void SetPenSpeed( int speed )
     {
-        penSpeed = speed;
+        m_penSpeed = speed;
     }
 
     virtual void SetPenNumber( int number )
     {
-        penNumber = number;
+        m_penNumber = number;
     }
 
     virtual void SetPenDiameter( double diameter );
@@ -212,17 +212,17 @@ protected:
     static void sortItems( std::list<HPGL_ITEM>& items );
 
     /// Return the plot command corresponding to a line type
-    static const char* lineTypeCommand( PLOT_DASH_TYPE linetype );
+    static const char* lineStyleCommand( PLOT_DASH_TYPE aLineStyle );
 
 protected:
-    int                  penSpeed;
-    int                  penNumber;
-    double               penDiameter;
-    double               arcTargetChordLength;
-    EDA_ANGLE            arcMinChordDegrees;
+    int                  m_penSpeed;
+    int                  m_penNumber;
+    double               m_penDiameter;
+    double               m_arcTargetChordLength;
+    EDA_ANGLE            m_arcMinChordDegrees;
     PLOT_DASH_TYPE       m_lineStyle;
-    bool                 useUserCoords;
-    bool                 fitUserCoords;
+    bool                 m_useUserCoords;
+    bool                 m_fitUserCoords;
 
     std::list<HPGL_ITEM> m_items;
     HPGL_ITEM*           m_current_item;