diff --git a/eeschema/dialogs/dialog_change_symbols.cpp b/eeschema/dialogs/dialog_change_symbols.cpp
index 801049aa32..ee36c71706 100644
--- a/eeschema/dialogs/dialog_change_symbols.cpp
+++ b/eeschema/dialogs/dialog_change_symbols.cpp
@@ -451,7 +451,7 @@ bool DIALOG_CHANGE_SYMBOLS::processSymbol( SCH_COMPONENT* aSymbol, SCH_SCREEN* a
     wxString  msg;
     wxString  references;
 
-    for( COMPONENT_INSTANCE_REFERENCE instance : aSymbol->GetInstanceReferences() )
+    for( SYMBOL_INSTANCE_REFERENCE instance : aSymbol->GetInstanceReferences() )
     {
         if( references.IsEmpty() )
             references = instance.m_Reference;
diff --git a/eeschema/lib_text.cpp b/eeschema/lib_text.cpp
index 65fd491c49..787374bb9e 100644
--- a/eeschema/lib_text.cpp
+++ b/eeschema/lib_text.cpp
@@ -272,8 +272,8 @@ void LIB_TEXT::Plot( PLOTTER* plotter, const wxPoint& offset, bool fill,
     bBox.RevertYAxis();
     wxPoint txtpos = bBox.Centre();
 
-    /* The text orientation may need to be flipped if the
-     * transformation matrix causes xy axes to be flipped. */
+    // The text orientation may need to be flipped if the transformation matrix causes xy
+    // axes to be flipped.
     int t1  = ( aTransform.x1 != 0 ) ^ ( GetTextAngle() != 0 );
     wxPoint pos = aTransform.TransformCoordinate( txtpos ) + offset;
 
@@ -308,12 +308,11 @@ void LIB_TEXT::print( RENDER_SETTINGS* aSettings, const wxPoint& aOffset, void*
     COLOR4D color = aSettings->GetLayerColor( LAYER_DEVICE );
     int     penWidth = std::max( GetEffectiveTextPenWidth(), aSettings->GetDefaultPenWidth() );
 
-    /* Calculate the text orientation, according to the component
-     * orientation/mirror (needed when draw text in schematic)
-     */
+    // Calculate the text orientation, according to the symbol orientation/mirror (needed when
+    // draw text in schematic)
     int orient = (int) GetTextAngle();
 
-    if( aTransform.y1 )  // Rotate component 90 degrees.
+    if( aTransform.y1 )  // Rotate symbol 90 degrees.
     {
         if( orient == TEXT_ANGLE_HORIZ )
             orient = TEXT_ANGLE_VERT;
@@ -321,16 +320,15 @@ void LIB_TEXT::print( RENDER_SETTINGS* aSettings, const wxPoint& aOffset, void*
             orient = TEXT_ANGLE_HORIZ;
     }
 
-    /* Calculate the text justification, according to the component
-     * orientation/mirror this is a bit complicated due to cumulative
-     * calculations:
+    /*
+     * Calculate the text justification, according to the symbol orientation/mirror.
+     * This is a bit complicated due to cumulative calculations:
      * - numerous cases (mirrored or not, rotation)
-     * - the DrawGraphicText function recalculate also H and H justifications
-     *      according to the text orientation.
-     * - When a component is mirrored, the text is not mirrored and
-     *   justifications are complicated to calculate
-     * so the more easily way is to use no justifications ( Centered text )
-     * and use GetBoundaryBox to know the text coordinate considered as centered
+     * - the GRText function will also recalculate H and V justifications according to the text
+     *   orientation.
+     * - When a symbol is mirrored, the text is not mirrored and justifications are complicated
+     *   to calculate so the more easily way is to use no justifications (centered text) and
+     *   use GetBoundingBox to know the text coordinate considered as centered
     */
     EDA_RECT bBox = GetBoundingBox();
 
diff --git a/eeschema/pin_number.cpp b/eeschema/pin_number.cpp
index f87dd3fa05..98801527a5 100644
--- a/eeschema/pin_number.cpp
+++ b/eeschema/pin_number.cpp
@@ -27,7 +27,7 @@
 
 namespace {
 
-wxString GetNextComponent( const wxString& str, wxString::size_type& cursor )
+wxString GetNextSymbol( const wxString& str, wxString::size_type& cursor )
 {
     if( str.size() <= cursor )
         return wxEmptyString;
@@ -113,44 +113,44 @@ int PinNumbers::Compare( const PinNumber& lhs, const PinNumber& rhs )
     wxString::size_type cursor1 = 0;
     wxString::size_type cursor2 = 0;
 
-    wxString comp1, comp2;
+    wxString symbol1, symbol2;
 
     for( ; ; )
     {
-        comp1 = GetNextComponent( lhs, cursor1 );
-        comp2 = GetNextComponent( rhs, cursor2 );
+        symbol1 = GetNextSymbol( lhs, cursor1 );
+        symbol2 = GetNextSymbol( rhs, cursor2 );
 
-        if( comp1.empty() && comp2.empty() )
+        if( symbol1.empty() && symbol2.empty() )
             return 0;
 
-        if( comp1.empty() )
+        if( symbol1.empty() )
             return -2;
 
-        if( comp2.empty() )
+        if( symbol2.empty() )
             return 2;
 
-        wxChar c1    = comp1[0];
-        wxChar c2    = comp2[0];
+        wxChar c1    = symbol1[0];
+        wxChar c2    = symbol2[0];
 
         if( wxIsdigit( c1 ) || c1 == '-' || c1 == '+' )
         {
             if( wxIsdigit( c2 ) || c2 == '-' || c2 == '+' )
             {
                 // numeric comparison
-                wxString::size_type v1 = comp1.find_first_of( "vV" );
+                wxString::size_type v1 = symbol1.find_first_of( "vV" );
 
                 if( v1 != wxString::npos )
-                    comp1[v1] = '.';
+                    symbol1[v1] = '.';
 
-                wxString::size_type v2 = comp2.find_first_of( "vV" );
+                wxString::size_type v2 = symbol2.find_first_of( "vV" );
 
                 if( v2 != wxString::npos )
-                    comp2[v2] = '.';
+                    symbol2[v2] = '.';
 
                 double val1, val2;
 
-                comp1.ToCDouble( &val1 );
-                comp2.ToCDouble( &val2 );
+                symbol1.ToCDouble( &val1 );
+                symbol2.ToCDouble( &val2 );
 
                 if( val1 < val2 )
                 {
@@ -176,7 +176,7 @@ int PinNumbers::Compare( const PinNumber& lhs, const PinNumber& rhs )
             if( wxIsdigit( c2 ) || c2 == '-' || c2 == '+' )
                 return 2;
 
-            int res = comp1.Cmp( comp2 );
+            int res = symbol1.Cmp( symbol2 );
 
             if( res != 0 )
                 return res;
diff --git a/eeschema/sch_component.cpp b/eeschema/sch_component.cpp
index 07b1f05dd8..26557204b8 100644
--- a/eeschema/sch_component.cpp
+++ b/eeschema/sch_component.cpp
@@ -394,7 +394,7 @@ void SCH_COMPONENT::AddHierarchicalReference( const KIID_PATH& aPath, const wxSt
         }
     }
 
-    COMPONENT_INSTANCE_REFERENCE instance;
+    SYMBOL_INSTANCE_REFERENCE instance;
     instance.m_Path = aPath;
     instance.m_Reference = aRef;
     instance.m_Unit = aUnit;
@@ -418,7 +418,7 @@ const wxString SCH_COMPONENT::GetRef( const SCH_SHEET_PATH* sheet, bool aInclude
     KIID_PATH path = sheet->Path();
     wxString  ref;
 
-    for( const COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+    for( const SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
     {
         if( instance.m_Path == path )
         {
@@ -469,7 +469,7 @@ void SCH_COMPONENT::SetRef( const SCH_SHEET_PATH* sheet, const wxString& ref )
     bool      notInArray = true;
 
     // check to see if it is already there before inserting it
-    for( COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+    for( SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
     {
         if( instance.m_Path == path )
         {
@@ -522,7 +522,7 @@ bool SCH_COMPONENT::IsAnnotated( const SCH_SHEET_PATH* aSheet )
 {
     KIID_PATH path = aSheet->Path();
 
-    for( const COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+    for( const SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
     {
         if( instance.m_Path == path )
             return instance.m_Reference.Last() != '?';
@@ -536,7 +536,7 @@ int SCH_COMPONENT::GetUnitSelection( const SCH_SHEET_PATH* aSheet ) const
 {
     KIID_PATH path = aSheet->Path();
 
-    for( const COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+    for( const SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
     {
         if( instance.m_Path == path )
             return instance.m_Unit;
@@ -553,7 +553,7 @@ void SCH_COMPONENT::SetUnitSelection( const SCH_SHEET_PATH* aSheet, int aUnitSel
     KIID_PATH path = aSheet->Path();
 
     // check to see if it is already there before inserting it
-    for( COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+    for( SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
     {
         if( instance.m_Path == path )
         {
@@ -571,7 +571,7 @@ const wxString SCH_COMPONENT::GetValue( const SCH_SHEET_PATH* sheet ) const
 {
     KIID_PATH path = sheet->Path();
 
-    for( const COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+    for( const SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
     {
         if( instance.m_Path == path && !instance.m_Value.IsEmpty() )
         {
@@ -590,7 +590,7 @@ void SCH_COMPONENT::SetValue( const SCH_SHEET_PATH* sheet, const wxString& aValu
     if( sheet == nullptr )
     {
         // Clear instance overrides and set primary field value
-        for( COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+        for( SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
             instance.m_Value = wxEmptyString;
 
         m_Fields[ VALUE_FIELD ].SetText( aValue );
@@ -600,7 +600,7 @@ void SCH_COMPONENT::SetValue( const SCH_SHEET_PATH* sheet, const wxString& aValu
     KIID_PATH path = sheet->Path();
 
     // check to see if it is already there before inserting it
-    for( COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+    for( SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
     {
         if( instance.m_Path == path )
         {
@@ -618,7 +618,7 @@ const wxString SCH_COMPONENT::GetFootprint( const SCH_SHEET_PATH* sheet ) const
 {
     KIID_PATH path = sheet->Path();
 
-    for( const COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+    for( const SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
     {
         if( instance.m_Path == path && !instance.m_Footprint.IsEmpty() )
         {
@@ -637,7 +637,7 @@ void SCH_COMPONENT::SetFootprint( const SCH_SHEET_PATH* sheet, const wxString& a
     if( sheet == nullptr )
     {
         // Clear instance overrides and set primary field value
-        for( COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+        for( SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
             instance.m_Footprint = wxEmptyString;
 
         m_Fields[ FOOTPRINT_FIELD ].SetText( aFootprint );
@@ -647,7 +647,7 @@ void SCH_COMPONENT::SetFootprint( const SCH_SHEET_PATH* sheet, const wxString& a
     KIID_PATH path = sheet->Path();
 
     // check to see if it is already there before inserting it
-    for( COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+    for( SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
     {
         if( instance.m_Path == path )
         {
@@ -990,7 +990,7 @@ void SCH_COMPONENT::ClearAnnotation( const SCH_SHEET_PATH* aSheetPath )
     {
         KIID_PATH path = aSheetPath->Path();
 
-        for( COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+        for( SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
         {
             if( instance.m_Path == path )
                 instance.m_Reference = defRef;
@@ -998,7 +998,7 @@ void SCH_COMPONENT::ClearAnnotation( const SCH_SHEET_PATH* aSheetPath )
     }
     else
     {
-        for( COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+        for( SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
             instance.m_Reference = defRef;
     }
 
@@ -1020,7 +1020,7 @@ bool SCH_COMPONENT::AddSheetPathReferenceEntryIfMissing( const KIID_PATH& aSheet
 
     wxString reference_path;
 
-    for( const COMPONENT_INSTANCE_REFERENCE& instance : m_instanceReferences )
+    for( const SYMBOL_INSTANCE_REFERENCE& instance : m_instanceReferences )
     {
         // if aSheetPath is found, nothing to do:
         if( instance.m_Path == aSheetPath )
@@ -1037,7 +1037,7 @@ bool SCH_COMPONENT::ReplaceInstanceSheetPath( const KIID_PATH& aOldSheetPath,
                                               const KIID_PATH& aNewSheetPath )
 {
     auto it = std::find_if( m_instanceReferences.begin(), m_instanceReferences.end(),
-                [ aOldSheetPath ]( COMPONENT_INSTANCE_REFERENCE& r )->bool
+                [ aOldSheetPath ]( SYMBOL_INSTANCE_REFERENCE& r )->bool
                 {
                     return aOldSheetPath == r.m_Path;
                 }
diff --git a/eeschema/sch_component.h b/eeschema/sch_component.h
index 1ee0e17f71..1335611b36 100644
--- a/eeschema/sch_component.h
+++ b/eeschema/sch_component.h
@@ -113,7 +113,7 @@ private:
 
     // Defines the hierarchical path and reference of the component.  This allows support
     // for multiple references to a single sub-sheet.
-    std::vector<COMPONENT_INSTANCE_REFERENCE> m_instanceReferences;
+    std::vector<SYMBOL_INSTANCE_REFERENCE> m_instanceReferences;
 
     void Init( const wxPoint& pos = wxPoint( 0, 0 ) );
 
@@ -162,7 +162,7 @@ public:
         return wxT( "SCH_COMPONENT" );
     }
 
-    const std::vector<COMPONENT_INSTANCE_REFERENCE>& GetInstanceReferences()
+    const std::vector<SYMBOL_INSTANCE_REFERENCE>& GetInstanceReferences()
     {
         return m_instanceReferences;
     }
diff --git a/eeschema/sch_edit_frame.cpp b/eeschema/sch_edit_frame.cpp
index a297411a5c..b05de38a8f 100644
--- a/eeschema/sch_edit_frame.cpp
+++ b/eeschema/sch_edit_frame.cpp
@@ -600,17 +600,17 @@ bool SCH_EDIT_FRAME::canCloseWindow( wxCloseEvent& aEvent )
     {
         auto* symbolEditor = (SYMBOL_EDIT_FRAME*) Kiway().Player( FRAME_SCH_SYMBOL_EDITOR, false );
 
-        if( symbolEditor && !symbolEditor->Close() )   // Can close component editor?
+        if( symbolEditor && !symbolEditor->Close() )   // Can close symbol editor?
             return false;
 
         auto* symbolViewer = (LIB_VIEW_FRAME*) Kiway().Player( FRAME_SCH_VIEWER, false );
 
-        if( symbolViewer && !symbolViewer->Close() )   // Can close component viewer?
+        if( symbolViewer && !symbolViewer->Close() )   // Can close symbol viewer?
             return false;
 
         symbolViewer = (LIB_VIEW_FRAME*) Kiway().Player( FRAME_SCH_VIEWER_MODAL, false );
 
-        if( symbolViewer && !symbolViewer->Close() )   // Can close modal component viewer?
+        if( symbolViewer && !symbolViewer->Close() )   // Can close modal symbol viewer?
             return false;
     }
 
@@ -1095,7 +1095,7 @@ void SCH_EDIT_FRAME::AddItemToScreenAndUndoList( SCH_SCREEN* aScreen, SCH_ITEM*
     wxCHECK_RET( aItem != NULL, wxT( "Cannot add null item to list." ) );
 
     SCH_SHEET*     parentSheet = nullptr;
-    SCH_COMPONENT* parentComponent = nullptr;
+    SCH_COMPONENT* parentSymbol = nullptr;
     SCH_ITEM*      undoItem = aItem;
 
     if( aItem->Type() == SCH_SHEET_PIN_T )
@@ -1103,19 +1103,19 @@ void SCH_EDIT_FRAME::AddItemToScreenAndUndoList( SCH_SCREEN* aScreen, SCH_ITEM*
         parentSheet = (SCH_SHEET*) aItem->GetParent();
 
         wxCHECK_RET( parentSheet && parentSheet->Type() == SCH_SHEET_T,
-                     wxT( "Cannot place sheet pin in invalid schematic sheet object." ) );
+                     wxT( "Cannot place sheet pin in invalid schematic sheet." ) );
 
         undoItem = parentSheet;
     }
 
     else if( aItem->Type() == SCH_FIELD_T )
     {
-        parentComponent = (SCH_COMPONENT*) aItem->GetParent();
+        parentSymbol = (SCH_COMPONENT*) aItem->GetParent();
 
-        wxCHECK_RET( parentComponent && parentComponent->Type() == SCH_COMPONENT_T,
-                     wxT( "Cannot place field in invalid schematic component object." ) );
+        wxCHECK_RET( parentSymbol && parentSymbol->Type() == SCH_COMPONENT_T,
+                     wxT( "Cannot place field in invalid schematic symbol." ) );
 
-        undoItem = parentComponent;
+        undoItem = parentSymbol;
     }
 
     if( aItem->IsNew() )
@@ -1129,8 +1129,8 @@ void SCH_EDIT_FRAME::AddItemToScreenAndUndoList( SCH_SCREEN* aScreen, SCH_ITEM*
         }
         else if( aItem->Type() == SCH_FIELD_T )
         {
-            // Component fields are also owned by their parent, but new component fields
-            // are handled elsewhere.
+            // Symbol fields are also owned by their parent, but new symbol fields are
+            // handled elsewhere.
             wxLogMessage( wxT( "addCurrentItemToScreen: unexpected new SCH_FIELD" ) );
         }
         else
@@ -1499,9 +1499,9 @@ const BOX2I SCH_EDIT_FRAME::GetDocumentExtents( bool aIncludeAllVisible ) const
             {
                 if( item->Type() == SCH_COMPONENT_T )
                 {
-                    // For components we need to get the bounding box without invisible text
-                    SCH_COMPONENT* comp = static_cast<SCH_COMPONENT*>( item );
-                    bBoxItems.Merge( comp->GetBoundingBox( false ) );
+                    // For symbols we need to get the bounding box without invisible text
+                    SCH_COMPONENT* symbol = static_cast<SCH_COMPONENT*>( item );
+                    bBoxItems.Merge( symbol->GetBoundingBox( false ) );
                 }
                 else
                     bBoxItems.Merge( item->GetBoundingBox() );
diff --git a/eeschema/sch_field.cpp b/eeschema/sch_field.cpp
index 2f3e53f0fa..76228fdcb5 100644
--- a/eeschema/sch_field.cpp
+++ b/eeschema/sch_field.cpp
@@ -109,12 +109,12 @@ wxString SCH_FIELD::GetShownText( int aDepth ) const
                 }
                 else
                 {
-                    SCH_COMPONENT* component = static_cast<SCH_COMPONENT*>( m_parent );
+                    SCH_COMPONENT* parentSymbol = static_cast<SCH_COMPONENT*>( m_parent );
 
-                    if( component->ResolveTextVar( token, aDepth + 1 ) )
+                    if( parentSymbol->ResolveTextVar( token, aDepth + 1 ) )
                         return true;
 
-                    SCHEMATIC* schematic = component->Schematic();
+                    SCHEMATIC* schematic = parentSymbol->Schematic();
                     SCH_SHEET* sheet = schematic ? schematic->CurrentSheet().Last() : nullptr;
 
                     if( sheet && sheet->ResolveTextVar( token, aDepth + 1 ) )
@@ -156,14 +156,14 @@ wxString SCH_FIELD::GetShownText( int aDepth ) const
 
     if( m_parent && m_parent->Type() == SCH_COMPONENT_T )
     {
-        SCH_COMPONENT* component = static_cast<SCH_COMPONENT*>( m_parent );
+        SCH_COMPONENT* parentSymbol = static_cast<SCH_COMPONENT*>( m_parent );
 
         if( m_id == REFERENCE_FIELD )
         {
             // For more than one part per package, we must add the part selection
             // A, B, ... or 1, 2, .. to the reference.
-            if( component->GetUnitCount() > 1 )
-                text << LIB_PART::SubReference( component->GetUnit() );
+            if( parentSymbol->GetUnitCount() > 1 )
+                text << LIB_PART::SubReference( parentSymbol->GetUnit() );
         }
     }
     else if( m_parent && m_parent->Type() == SCH_SHEET_T )
@@ -193,14 +193,14 @@ void SCH_FIELD::Print( RENDER_SETTINGS* aSettings, const wxPoint& aOffset )
     if( ( !IsVisible() && !IsForceVisible() ) || IsVoid() )
         return;
 
-    // Calculate the text orientation according to the component orientation.
+    // Calculate the text orientation according to the symbol orientation.
     orient = GetTextAngle();
 
     if( m_parent && m_parent->Type() == SCH_COMPONENT_T )
     {
-        SCH_COMPONENT* parentComponent = static_cast<SCH_COMPONENT*>( m_parent );
+        SCH_COMPONENT* parentSymbol = static_cast<SCH_COMPONENT*>( m_parent );
 
-        if( parentComponent && parentComponent->GetTransform().y1 )  // Rotate component 90 degrees.
+        if( parentSymbol && parentSymbol->GetTransform().y1 )  // Rotate symbol 90 degrees.
         {
             if( orient == TEXT_ANGLE_HORIZ )
                 orient = TEXT_ANGLE_VERT;
@@ -209,16 +209,15 @@ void SCH_FIELD::Print( RENDER_SETTINGS* aSettings, const wxPoint& aOffset )
         }
     }
 
-    /* Calculate the text justification, according to the component
-     * orientation/mirror this is a bit complicated due to cumulative
-     * calculations:
+    /*
+     * Calculate the text justification, according to the symbol orientation/mirror.
+     * This is a bit complicated due to cumulative calculations:
      * - numerous cases (mirrored or not, rotation)
-     * - the DrawGraphicText function recalculate also H and H justifications
-     *      according to the text orientation.
-     * - When a component is mirrored, the text is not mirrored and
-     *   justifications are complicated to calculate
-     * so the more easily way is to use no justifications ( Centered text )
-     * and use GetBoundaryBox to know the text coordinate considered as centered
+     * - the GRText function will also recalculate H and V justifications according to the text
+     *   orientation.
+     * - When a symbol is mirrored, the text is not mirrored and justifications are complicated
+     *   to calculate so the more easily way is to use no justifications (centered text) and use
+     *   GetBoundingBox to know the text coordinate considered as centered
      */
     EDA_RECT boundaryBox = GetBoundingBox();
     textpos = boundaryBox.Centre() + aOffset;
@@ -260,19 +259,19 @@ const EDA_RECT SCH_FIELD::GetBoundingBox() const
     RotatePoint( &begin, pos, GetTextAngle() );
     RotatePoint( &end, pos, GetTextAngle() );
 
-    // Now, apply the component transform (mirror/rot)
+    // Now, apply the symbol transform (mirror/rot)
     TRANSFORM transform;
 
     if( m_parent && m_parent->Type() == SCH_COMPONENT_T )
     {
-        SCH_COMPONENT* parentComponent = static_cast<SCH_COMPONENT*>( m_parent );
+        SCH_COMPONENT* parentSymbol = static_cast<SCH_COMPONENT*>( m_parent );
 
         // Due to the Y axis direction, we must mirror the bounding box,
         // relative to the text position:
         MIRROR( begin.y, pos.y );
         MIRROR( end.y,   pos.y );
 
-        transform = parentComponent->GetTransform();
+        transform = parentSymbol->GetTransform();
     }
     else
     {
@@ -331,20 +330,20 @@ bool SCH_FIELD::Matches( wxFindReplaceData& aSearchData, void* aAuxData )
         if( searchAndReplace && !replaceReferences )
             return false;
 
-        SCH_COMPONENT* parentComponent = static_cast<SCH_COMPONENT*>( m_parent );
+        SCH_COMPONENT* parentSymbol = static_cast<SCH_COMPONENT*>( m_parent );
         wxASSERT( aAuxData );
 
         // Take sheet path into account which effects the reference field and the unit for
-        // components with multiple parts.
+        // symbols with multiple parts.
         if( aAuxData )
         {
-            text = parentComponent->GetRef( (SCH_SHEET_PATH*) aAuxData );
+            text = parentSymbol->GetRef((SCH_SHEET_PATH*) aAuxData );
 
             if( SCH_ITEM::Matches( text, aSearchData ) )
                 return true;
 
-            if( parentComponent->GetUnitCount() > 1 )
-                text << LIB_PART::SubReference( parentComponent->GetUnit() );
+            if( parentSymbol->GetUnitCount() > 1 )
+                text << LIB_PART::SubReference( parentSymbol->GetUnit() );
         }
     }
 
@@ -356,11 +355,11 @@ bool SCH_FIELD::IsReplaceable() const
 {
     if( m_parent && m_parent->Type() == SCH_COMPONENT_T )
     {
-        SCH_COMPONENT* parentComponent = static_cast<SCH_COMPONENT*>( m_parent );
+        SCH_COMPONENT* parentSymbol = static_cast<SCH_COMPONENT*>( m_parent );
 
         if( m_id == VALUE_FIELD )
         {
-            LIB_PART* part = parentComponent->GetPartRef().get();
+            LIB_PART* part = parentSymbol->GetPartRef().get();
 
             if( part && part->IsPower() )
                 return false;
@@ -383,7 +382,7 @@ bool SCH_FIELD::Replace( wxFindReplaceData& aSearchData, void* aAuxData )
 
     if( m_parent && m_parent->Type() == SCH_COMPONENT_T )
     {
-        SCH_COMPONENT* parentComponent = static_cast<SCH_COMPONENT*>( m_parent );
+        SCH_COMPONENT* parentSymbol = static_cast<SCH_COMPONENT*>( m_parent );
 
         if( m_id == REFERENCE_FIELD )
         {
@@ -393,12 +392,12 @@ bool SCH_FIELD::Replace( wxFindReplaceData& aSearchData, void* aAuxData )
             if( !( aSearchData.GetFlags() & FR_REPLACE_REFERENCES ) )
                 return false;
 
-            wxString text = parentComponent->GetRef( (SCH_SHEET_PATH*) aAuxData );
+            wxString text = parentSymbol->GetRef((SCH_SHEET_PATH*) aAuxData );
 
             isReplaced = EDA_ITEM::Replace( aSearchData, text );
 
             if( isReplaced )
-                parentComponent->SetRef( (SCH_SHEET_PATH*) aAuxData, text );
+                parentSymbol->SetRef((SCH_SHEET_PATH*) aAuxData, text );
         }
         else
         {
@@ -540,14 +539,14 @@ void SCH_FIELD::Plot( PLOTTER* aPlotter )
     if( IsVoid() )
         return;
 
-    // Calculate the text orientation, according to the component orientation/mirror
+    // Calculate the text orientation, according to the symbol orientation/mirror
     int orient = GetTextAngle();
 
     if( m_parent && m_parent->Type() == SCH_COMPONENT_T )
     {
-        SCH_COMPONENT* parentComponent = static_cast<SCH_COMPONENT*>( m_parent );
+        SCH_COMPONENT* parentSymbol = static_cast<SCH_COMPONENT*>( m_parent );
 
-        if( parentComponent->GetTransform().y1 )  // Rotate component 90 deg.
+        if( parentSymbol->GetTransform().y1 )  // Rotate symbol 90 deg.
         {
             if( orient == TEXT_ANGLE_HORIZ )
                 orient = TEXT_ANGLE_VERT;
@@ -557,15 +556,14 @@ void SCH_FIELD::Plot( PLOTTER* aPlotter )
     }
 
     /*
-     * Calculate the text justification, according to the component orientation/mirror
-     * this is a bit complicated due to cumulative calculations:
+     * Calculate the text justification, according to the symbol orientation/mirror.
+     * This is a bit complicated due to cumulative calculations:
      * - numerous cases (mirrored or not, rotation)
-     * - the DrawGraphicText function also recalculates H and H justifications according to the
-     *   text orientation.
-     * - When a component is mirrored, the text is not mirrored and justifications are
-     *   complicated to calculate
-     * so the easier way is to use no justifications (centered text) and use GetBoundaryBox to
-     * know the text coordinate considered as centered
+     * - the plotter's Text function will also recalculate H and V justifications according to
+     *   the text orientation.
+     * - When a symbol is mirrored, the text is not mirrored and justifications are complicated
+     *   to calculate so the easier way is to use no justifications (centered text) and use
+     *   GetBoundingBox to know the text coordinate considered as centered
      */
     EDA_RECT BoundaryBox = GetBoundingBox();
     EDA_TEXT_HJUSTIFY_T hjustify = GR_TEXT_HJUSTIFY_CENTER;
diff --git a/eeschema/sch_item.cpp b/eeschema/sch_item.cpp
index e1b310d486..43f46cf215 100644
--- a/eeschema/sch_item.cpp
+++ b/eeschema/sch_item.cpp
@@ -86,12 +86,12 @@ SCH_ITEM* SCH_ITEM::Duplicate( bool doClone ) const
 
     if( newItem->Type() == SCH_COMPONENT_T )
     {
-        SCH_COMPONENT* component = (SCH_COMPONENT*) newItem;
+        SCH_COMPONENT* symbol = (SCH_COMPONENT*) newItem;
 
-        for( SCH_PIN* pin : component->GetPins() )
+        for( SCH_PIN* pin : symbol->GetPins() )
             pin->ClearFlags( SELECTED | BRIGHTENED );
 
-        for( SCH_FIELD& field : component->GetFields() )
+        for( SCH_FIELD& field : symbol->GetFields() )
             field.ClearFlags( SELECTED | BRIGHTENED );
     }
 
diff --git a/eeschema/sch_item.h b/eeschema/sch_item.h
index c784571cd5..fcb36bc82b 100644
--- a/eeschema/sch_item.h
+++ b/eeschema/sch_item.h
@@ -243,7 +243,7 @@ public:
      * @return true for items which are moved with the anchor point at mouse cursor
      *  and false for items moved with no reference to anchor
      * Usually return true for small items (labels, junctions) and false for
-     * items which can be large (hierarchical sheets, compoments)
+     * items which can be large (hierarchical sheets, symbols)
      */
     virtual bool IsMovableFromAnchorPoint() { return true; }
 
@@ -254,7 +254,7 @@ public:
      * Searches the item hierarchy to find a SCHEMATIC
      *
      * Every SCH_ITEM that lives on a SCH_SCREEN should be parented to either that screen
-     * or another SCH_ITEM on the same screen (for example, pins to their components).
+     * or another SCH_ITEM on the same screen (for example, pins to their symbols).
      *
      * Every SCH_SCREEN should be parented to the SCHEMATIC.
      * Note that this hierarchy is not the same as the sheet hierarchy!
@@ -456,8 +456,7 @@ public:
      *
      * Fields that have been moved by hand are not automatically placed.
      *
-     * @param aScreen is the SCH_SCREEN associated with the current instance of the
-     *                component.
+     * @param aScreen is the SCH_SCREEN associated with the current instance of the symbol.
      */
     void AutoAutoplaceFields( SCH_SCREEN* aScreen )
     {
diff --git a/eeschema/sch_painter.cpp b/eeschema/sch_painter.cpp
index 3b0424cc66..1d665709e8 100644
--- a/eeschema/sch_painter.cpp
+++ b/eeschema/sch_painter.cpp
@@ -120,7 +120,7 @@ EESCHEMA_SETTINGS* eeconfig()
 
 /**
  * Used when a LIB_PART is not found in library to draw a dummy shape.
- * This component is a 400 mils square with the text "??"
+ * This symbol is a 400 mils square with the text "??"
  *
  *   DEF DUMMY U 0 40 Y Y 1 0 N
  *     F0 "U" 0 -350 60 H V
@@ -1422,13 +1422,13 @@ static void orientPart( LIB_PART* part, int orientation )
 }
 
 
-void SCH_PAINTER::draw( SCH_COMPONENT *aComp, int aLayer )
+void SCH_PAINTER::draw( SCH_COMPONENT *aSymbol, int aLayer )
 {
-    int unit = aComp->GetUnitSelection( &m_schematic->CurrentSheet() );
-    int convert = aComp->GetConvert();
+    int unit = aSymbol->GetUnitSelection( &m_schematic->CurrentSheet() );
+    int convert = aSymbol->GetConvert();
 
     // Use dummy part if the actual couldn't be found (or couldn't be locked).
-    LIB_PART* originalPart = aComp->GetPartRef() ? aComp->GetPartRef().get() : dummy();
+    LIB_PART* originalPart = aSymbol->GetPartRef() ? aSymbol->GetPartRef().get() : dummy();
     LIB_PINS  originalPins;
     originalPart->GetPins( originalPins, unit, convert );
 
@@ -1437,37 +1437,37 @@ void SCH_PAINTER::draw( SCH_COMPONENT *aComp, int aLayer )
     LIB_PINS tempPins;
     tempPart.GetPins( tempPins, unit, convert );
 
-    tempPart.SetFlags( aComp->GetFlags() );
+    tempPart.SetFlags( aSymbol->GetFlags() );
 
-    orientPart( &tempPart, aComp->GetOrientation() );
+    orientPart( &tempPart, aSymbol->GetOrientation() );
 
     for( auto& tempItem : tempPart.GetDrawItems() )
     {
-        tempItem.SetFlags( aComp->GetFlags() );     // SELECTED, HIGHLIGHTED, BRIGHTENED
-        tempItem.MoveTo( tempItem.GetPosition() + (wxPoint) mapCoords( aComp->GetPosition() ) );
+        tempItem.SetFlags( aSymbol->GetFlags() );     // SELECTED, HIGHLIGHTED, BRIGHTENED
+        tempItem.MoveTo( tempItem.GetPosition() + (wxPoint) mapCoords( aSymbol->GetPosition() ) );
     }
 
-    // Copy the pin info from the component to the temp pins
+    // Copy the pin info from the symbol to the temp pins
     for( unsigned i = 0; i < tempPins.size(); ++ i )
     {
-        SCH_PIN* compPin = aComp->GetPin( originalPins[ i ] );
+        SCH_PIN* symbolPin = aSymbol->GetPin( originalPins[ i ] );
         LIB_PIN* tempPin = tempPins[ i ];
 
         tempPin->ClearFlags();
-        tempPin->SetFlags( compPin->GetFlags() );     // SELECTED, HIGHLIGHTED, BRIGHTENED
+        tempPin->SetFlags( symbolPin->GetFlags() );     // SELECTED, HIGHLIGHTED, BRIGHTENED
 
-        tempPin->SetName( compPin->GetName() );
-        tempPin->SetType( compPin->GetType() );
-        tempPin->SetShape( compPin->GetShape() );
+        tempPin->SetName( symbolPin->GetName() );
+        tempPin->SetType( symbolPin->GetType() );
+        tempPin->SetShape( symbolPin->GetShape() );
 
-        if( compPin->IsDangling() )
+        if( symbolPin->IsDangling() )
             tempPin->SetFlags( IS_DANGLING );
     }
 
-    draw( &tempPart, aLayer, false, aComp->GetUnit(), aComp->GetConvert() );
+    draw( &tempPart, aLayer, false, aSymbol->GetUnit(), aSymbol->GetConvert() );
 
     // The fields are SCH_COMPONENT-specific so don't need to be copied/oriented/translated
-    for( SCH_FIELD& field : aComp->GetFields() )
+    for( SCH_FIELD& field : aSymbol->GetFields() )
         draw( &field, aLayer );
 }
 
@@ -1507,7 +1507,7 @@ void SCH_PAINTER::draw( SCH_FIELD *aField, int aLayer )
     {
         if( static_cast<SCH_COMPONENT*>( aField->GetParent() )->GetTransform().y1 )
         {
-        // Rotate component 90 degrees.
+        // Rotate symbol 90 degrees.
         if( orient == TEXT_ANGLE_HORIZ )
             orient = TEXT_ANGLE_VERT;
         else
@@ -1515,15 +1515,15 @@ void SCH_PAINTER::draw( SCH_FIELD *aField, int aLayer )
         }
     }
 
-    /* Calculate the text justification, according to the component orientation/mirror.
+    /*
+     * Calculate the text justification, according to the symbol orientation/mirror.
      * This is a bit complicated due to cumulative calculations:
      * - numerous cases (mirrored or not, rotation)
      * - the DrawGraphicText function recalculate also H and H justifications according to the
      *   text orientation.
-     * - When a component is mirrored, the text is not mirrored and justifications are
-     *   complicated to calculate
-     * so the easier way is to use no justifications (centered text) and use GetBoundingBox
-     * to know the text coordinate considered as centered
+     * - when symbol is mirrored, the text is not mirrored and justifications are complicated
+     *   to calculate so the easier way is to use no justifications (centered text) and use
+     *   GetBoundingBox to know the text coordinate considered as centered
      */
     EDA_RECT boundaryBox = aField->GetBoundingBox();
     wxPoint textpos = boundaryBox.Centre();
diff --git a/eeschema/sch_painter.h b/eeschema/sch_painter.h
index 03ed5b6e5b..543d52525f 100644
--- a/eeschema/sch_painter.h
+++ b/eeschema/sch_painter.h
@@ -165,7 +165,7 @@ private:
     void draw( LIB_FIELD* aField, int aLayer );
     void draw( LIB_TEXT* aText, int aLayer );
     void draw( LIB_BEZIER* aCurve, int aLayer );
-    void draw( SCH_COMPONENT* aComp, int aLayer );
+    void draw( SCH_COMPONENT* aSymbol, int aLayer );
     void draw( SCH_JUNCTION* aJct, int aLayer );
     void draw( SCH_FIELD* aField, int aLayer );
     void draw( SCH_TEXT* aText, int aLayer );
diff --git a/eeschema/sch_pin.cpp b/eeschema/sch_pin.cpp
index 731aa60844..dcf1295935 100644
--- a/eeschema/sch_pin.cpp
+++ b/eeschema/sch_pin.cpp
@@ -26,8 +26,8 @@
 #include <sch_edit_frame.h>
 
 
-SCH_PIN::SCH_PIN( LIB_PIN* aLibPin, SCH_COMPONENT* aParentComponent ) :
-    SCH_ITEM( aParentComponent, SCH_PIN_T )
+SCH_PIN::SCH_PIN( LIB_PIN* aLibPin, SCH_COMPONENT* aParentSymbol ) :
+    SCH_ITEM( aParentSymbol, SCH_PIN_T )
 {
     m_alt = wxEmptyString;
     m_number = aLibPin->GetNumber();
@@ -41,9 +41,8 @@ SCH_PIN::SCH_PIN( LIB_PIN* aLibPin, SCH_COMPONENT* aParentComponent ) :
  * Create a proxy pin from an alternate pin designation.
  * The LIB_PIN data will be filled in when the pin is resolved (see SCH_COMPONENT::UpdatePins).
  */
-SCH_PIN::SCH_PIN( SCH_COMPONENT* aParentComponent, const wxString& aNumber,
-                  const wxString& aAlt ) :
-    SCH_ITEM( aParentComponent, SCH_PIN_T )
+SCH_PIN::SCH_PIN( SCH_COMPONENT* aParentSymbol, const wxString& aNumber, const wxString& aAlt ) :
+    SCH_ITEM( aParentSymbol, SCH_PIN_T )
 {
     m_alt = aAlt;
     m_number = aNumber;
@@ -248,7 +247,7 @@ wxString SCH_PIN::GetDefaultNetName( const SCH_SHEET_PATH& aPath )
 
     bool annotated = true;
 
-    // Add timestamp for uninitialized components
+    // Add timestamp for uninitialized symbols
     if( name.Last() == '?' )
     {
         name << GetParentSymbol()->m_Uuid.AsString();
diff --git a/eeschema/sch_pin.h b/eeschema/sch_pin.h
index ce19df779a..e8d5c1d32d 100644
--- a/eeschema/sch_pin.h
+++ b/eeschema/sch_pin.h
@@ -46,9 +46,9 @@ class SCH_PIN : public SCH_ITEM
     std::map<const SCH_SHEET_PATH, wxString> m_net_name_map;
 
 public:
-    SCH_PIN( LIB_PIN* aLibPin, SCH_COMPONENT* aParentComponent );
+    SCH_PIN( LIB_PIN* aLibPin, SCH_COMPONENT* aParentSymbol );
 
-    SCH_PIN( SCH_COMPONENT* aParentComponent, const wxString& aNumber, const wxString& aAlt );
+    SCH_PIN( SCH_COMPONENT* aParentSymbol, const wxString& aNumber, const wxString& aAlt );
 
     SCH_PIN( const SCH_PIN& aPin );
 
diff --git a/eeschema/sch_plugins/kicad/sch_sexpr_parser.cpp b/eeschema/sch_plugins/kicad/sch_sexpr_parser.cpp
index e9326724f6..c1ecef09ca 100644
--- a/eeschema/sch_plugins/kicad/sch_sexpr_parser.cpp
+++ b/eeschema/sch_plugins/kicad/sch_sexpr_parser.cpp
@@ -1878,7 +1878,7 @@ void SCH_SEXPR_PARSER::parseSchSymbolInstances( SCH_SCREEN* aScreen )
         {
             NeedSYMBOL();
 
-            COMPONENT_INSTANCE_REFERENCE instance;
+            SYMBOL_INSTANCE_REFERENCE instance;
 
             instance.m_Path = KIID_PATH( FromUTF8() );
 
diff --git a/eeschema/sch_plugins/kicad/sch_sexpr_plugin.cpp b/eeschema/sch_plugins/kicad/sch_sexpr_plugin.cpp
index c02df140e1..01942f7165 100644
--- a/eeschema/sch_plugins/kicad/sch_sexpr_plugin.cpp
+++ b/eeschema/sch_plugins/kicad/sch_sexpr_plugin.cpp
@@ -768,7 +768,7 @@ void SCH_SEXPR_PLUGIN::Format( SCH_SHEET* aSheet )
             m_out->Print( 0, "\n" );
             m_out->Print( 1, "(symbol_instances\n" );
 
-            for( const COMPONENT_INSTANCE_REFERENCE& instance : screen->m_symbolInstances )
+            for( const SYMBOL_INSTANCE_REFERENCE& instance : screen->m_symbolInstances )
             {
                 m_out->Print( 2, "(path %s (reference %s) (unit %d))\n",
                               m_out->Quotew( instance.m_Path.AsString() ).c_str(),
diff --git a/eeschema/sch_plugins/legacy/sch_legacy_plugin.cpp b/eeschema/sch_plugins/legacy/sch_legacy_plugin.cpp
index ed4af29b0b..c6c08371a2 100644
--- a/eeschema/sch_plugins/legacy/sch_legacy_plugin.cpp
+++ b/eeschema/sch_plugins/legacy/sch_legacy_plugin.cpp
@@ -1997,7 +1997,7 @@ void SCH_LEGACY_PLUGIN::saveComponent( SCH_COMPONENT* aComponent )
     // This is redundant with the AR entries below, but it makes the files backwards-compatible.
     if( aComponent->GetInstanceReferences().size() > 0 )
     {
-        const COMPONENT_INSTANCE_REFERENCE& instance = aComponent->GetInstanceReferences()[0];
+        const SYMBOL_INSTANCE_REFERENCE& instance = aComponent->GetInstanceReferences()[0];
         name1 = toUTFTildaText( instance.m_Reference );
     }
     else
@@ -2040,7 +2040,7 @@ void SCH_LEGACY_PLUGIN::saveComponent( SCH_COMPONENT* aComponent )
      */
     if( aComponent->GetInstanceReferences().size() > 1 )
     {
-        for( const COMPONENT_INSTANCE_REFERENCE& instance : aComponent->GetInstanceReferences() )
+        for( const SYMBOL_INSTANCE_REFERENCE& instance : aComponent->GetInstanceReferences() )
         {
             /*format:
              * AR Path="/140/2" Ref="C99"   Part="1"
diff --git a/eeschema/sch_rtree.h b/eeschema/sch_rtree.h
index 7e2549fdc9..1db374ea78 100644
--- a/eeschema/sch_rtree.h
+++ b/eeschema/sch_rtree.h
@@ -176,7 +176,7 @@ public:
      *
      * for( auto item : rtree.OfType( SCH_COMPONENT_T ) )
      *
-     * and iterate over the RTree items that are components only
+     * and iterate over the RTree items that are symbols only
      */
     struct EE_TYPE
     {
diff --git a/eeschema/sch_screen.cpp b/eeschema/sch_screen.cpp
index 91aaa3b77e..f8fbfcc70d 100644
--- a/eeschema/sch_screen.cpp
+++ b/eeschema/sch_screen.cpp
@@ -836,36 +836,36 @@ void SCH_SCREEN::ClearDrawingState()
 }
 
 
-LIB_PIN* SCH_SCREEN::GetPin( const wxPoint& aPosition, SCH_COMPONENT** aComponent,
+LIB_PIN* SCH_SCREEN::GetPin( const wxPoint& aPosition, SCH_COMPONENT** aSymbol,
                              bool aEndPointOnly )
 {
-    SCH_COMPONENT*  component = NULL;
+    SCH_COMPONENT*  candidate = NULL;
     LIB_PIN*        pin = NULL;
 
     for( SCH_ITEM* item : Items().Overlapping( SCH_COMPONENT_T, aPosition ) )
     {
-        component = static_cast<SCH_COMPONENT*>( item );
+        candidate = static_cast<SCH_COMPONENT*>( item );
 
         if( aEndPointOnly )
         {
             pin = NULL;
 
-            if( !component->GetPartRef() )
+            if( !candidate->GetPartRef() )
                 continue;
 
-            for( pin = component->GetPartRef()->GetNextPin(); pin;
-                 pin = component->GetPartRef()->GetNextPin( pin ) )
+            for( pin = candidate->GetPartRef()->GetNextPin(); pin;
+                 pin = candidate->GetPartRef()->GetNextPin( pin ) )
             {
                 // Skip items not used for this part.
-                if( component->GetUnit() && pin->GetUnit() &&
-                    ( pin->GetUnit() != component->GetUnit() ) )
+                if( candidate->GetUnit() && pin->GetUnit() &&
+                    ( pin->GetUnit() != candidate->GetUnit() ) )
                     continue;
 
-                if( component->GetConvert() && pin->GetConvert() &&
-                    ( pin->GetConvert() != component->GetConvert() ) )
+                if( candidate->GetConvert() && pin->GetConvert() &&
+                    ( pin->GetConvert() != candidate->GetConvert() ) )
                     continue;
 
-                if(component->GetPinPhysicalPosition( pin ) == aPosition )
+                if( candidate->GetPinPhysicalPosition( pin ) == aPosition )
                     break;
             }
             if( pin )
@@ -873,15 +873,15 @@ LIB_PIN* SCH_SCREEN::GetPin( const wxPoint& aPosition, SCH_COMPONENT** aComponen
         }
         else
         {
-            pin = (LIB_PIN*) component->GetDrawItem( aPosition, LIB_PIN_T );
+            pin = (LIB_PIN*) candidate->GetDrawItem( aPosition, LIB_PIN_T );
 
             if( pin )
                 break;
         }
     }
 
-    if( pin && aComponent )
-        *aComponent = component;
+    if( pin && aSymbol )
+        *aSymbol = candidate;
 
     return pin;
 }
@@ -924,9 +924,9 @@ void SCH_SCREEN::ClearAnnotation( SCH_SHEET_PATH* aSheetPath )
 
     for( SCH_ITEM* item : Items().OfType( SCH_COMPONENT_T ) )
     {
-        SCH_COMPONENT* component = static_cast<SCH_COMPONENT*>( item );
+        SCH_COMPONENT* symbol = static_cast<SCH_COMPONENT*>( item );
 
-        component->ClearAnnotation( aSheetPath );
+        symbol->ClearAnnotation( aSheetPath );
     }
 }
 
@@ -938,11 +938,11 @@ void SCH_SCREEN::EnsureAlternateReferencesExist()
 
     for( SCH_ITEM* item : Items().OfType( SCH_COMPONENT_T ) )
     {
-        SCH_COMPONENT* component = static_cast<SCH_COMPONENT*>( item );
+        SCH_COMPONENT* symbol = static_cast<SCH_COMPONENT*>( item );
 
         // Add (when not existing) all sheet path entries
         for( const SCH_SHEET_PATH& sheet : GetClientSheetPaths() )
-            component->AddSheetPathReferenceEntryIfMissing( sheet.Path() );
+            symbol->AddSheetPathReferenceEntryIfMissing( sheet.Path() );
     }
 }
 
@@ -1206,8 +1206,7 @@ void SCH_SCREENS::ClearAnnotationOfNewSheetPaths( SCH_SHEET_LIST& aInitialSheetP
 
     wxCHECK_RET( sch, "Null schematic in SCH_SCREENS::ClearAnnotationOfNewSheetPaths" );
 
-    // Clear the annotation for the components inside new sheetpaths
-    // not already in aInitialSheetList
+    // Clear the annotation for symbols inside new sheetpaths not already in aInitialSheetList
     SCH_SCREENS screensList( sch->Root() );     // The list of screens, shared by sheet paths
     screensList.BuildClientSheetPathList();     // build the shared by sheet paths, by screen
 
@@ -1392,7 +1391,7 @@ bool SCH_SCREENS::HasNoFullyDefinedLibIds()
         for( auto item : screen->Items().OfType( SCH_COMPONENT_T ) )
         {
             cnt++;
-            auto symbol = static_cast<SCH_COMPONENT*>( item );
+            SCH_COMPONENT* symbol = static_cast<SCH_COMPONENT*>( item );
 
             if( !symbol->GetLibId().GetLibNickname().empty() )
                 return false;
@@ -1409,8 +1408,8 @@ size_t SCH_SCREENS::GetLibNicknames( wxArrayString& aLibNicknames )
     {
         for( auto item : screen->Items().OfType( SCH_COMPONENT_T ) )
         {
-            auto  symbol   = static_cast<SCH_COMPONENT*>( item );
-            auto& nickname = symbol->GetLibId().GetLibNickname();
+            SCH_COMPONENT* symbol   = static_cast<SCH_COMPONENT*>( item );
+            const UTF8&    nickname = symbol->GetLibId().GetLibNickname();
 
             if( !nickname.empty() && ( aLibNicknames.Index( nickname ) == wxNOT_FOUND ) )
                 aLibNicknames.Add( nickname );
diff --git a/eeschema/sch_screen.h b/eeschema/sch_screen.h
index 0f7ea55478..10d2267927 100644
--- a/eeschema/sch_screen.h
+++ b/eeschema/sch_screen.h
@@ -136,7 +136,7 @@ private:
      *          schematic file is loaded.  It is read only and it is only written to non-root
      *          schematic files.
      */
-    std::vector<COMPONENT_INSTANCE_REFERENCE> m_symbolInstances;
+    std::vector<SYMBOL_INSTANCE_REFERENCE> m_symbolInstances;
     std::vector<SCH_SHEET_INSTANCE> m_sheetInstances;
 
     friend SCH_EDIT_FRAME;     // Only to populate m_symbolInstances.
@@ -369,12 +369,12 @@ public:
      * Test the screen for a component pin item at \a aPosition.
      *
      * @param aPosition Position to test.
-     * @param aComponent The component if a pin was found, otherwise NULL.
+     * @param aSymbol The component if a pin was found, otherwise NULL.
      * @param aEndPointOnly Set to true to test if \a aPosition is the connection
      *                      point of the pin.
      * @return The pin item if found, otherwise NULL.
      */
-    LIB_PIN* GetPin( const wxPoint& aPosition, SCH_COMPONENT** aComponent = NULL,
+    LIB_PIN* GetPin( const wxPoint& aPosition, SCH_COMPONENT** aSymbol = NULL,
                      bool aEndPointOnly = false );
 
     /**
@@ -493,7 +493,7 @@ public:
         return m_aliases;
     }
 
-    const std::vector<COMPONENT_INSTANCE_REFERENCE>& GetSymbolInstances() const
+    const std::vector<SYMBOL_INSTANCE_REFERENCE>& GetSymbolInstances() const
     {
         return m_symbolInstances;
     }
diff --git a/eeschema/sch_sheet.cpp b/eeschema/sch_sheet.cpp
index 3737697ee5..63673fa69e 100644
--- a/eeschema/sch_sheet.cpp
+++ b/eeschema/sch_sheet.cpp
@@ -605,7 +605,7 @@ wxPoint SCH_SHEET::GetRotationCenter() const
 }
 
 
-int SCH_SHEET::ComponentCount() const
+int SCH_SHEET::SymbolCount() const
 {
     int n = 0;
 
@@ -613,14 +613,14 @@ int SCH_SHEET::ComponentCount() const
     {
         for( SCH_ITEM* aItem : m_screen->Items().OfType( SCH_COMPONENT_T ) )
         {
-            SCH_COMPONENT* comp = (SCH_COMPONENT*) aItem;
+            SCH_COMPONENT* symbol = (SCH_COMPONENT*) aItem;
 
-            if( comp->GetField( VALUE_FIELD )->GetText().GetChar( 0 ) != '#' )
+            if( symbol->GetField( VALUE_FIELD )->GetText().GetChar( 0 ) != '#' )
                 n++;
         }
 
         for( SCH_ITEM* aItem : m_screen->Items().OfType( SCH_SHEET_T ) )
-            n += static_cast<const SCH_SHEET*>( aItem )->ComponentCount();
+            n += static_cast<const SCH_SHEET*>( aItem )->SymbolCount();
     }
 
     return n;
diff --git a/eeschema/sch_sheet.h b/eeschema/sch_sheet.h
index 14b5fad5b3..b3bc09a3c3 100644
--- a/eeschema/sch_sheet.h
+++ b/eeschema/sch_sheet.h
@@ -460,7 +460,7 @@ public:
      *
      *  @return the component count.
      */
-    int ComponentCount() const;
+    int SymbolCount() const;
 
     /**
      * Search the existing hierarchy for an instance of screen loaded from \a aFileName.
diff --git a/eeschema/sch_sheet_path.cpp b/eeschema/sch_sheet_path.cpp
index ead002f888..d091505ccd 100644
--- a/eeschema/sch_sheet_path.cpp
+++ b/eeschema/sch_sheet_path.cpp
@@ -774,7 +774,7 @@ SCH_SHEET_PATH* SCH_SHEET_LIST::FindSheetForScreen( SCH_SCREEN* aScreen )
 
 
 void SCH_SHEET_LIST::UpdateSymbolInstances(
-                                const std::vector<COMPONENT_INSTANCE_REFERENCE>& aSymbolInstances )
+                                const std::vector<SYMBOL_INSTANCE_REFERENCE>& aSymbolInstances )
 {
     SCH_REFERENCE_LIST symbolInstances;
 
@@ -800,7 +800,7 @@ void SCH_SHEET_LIST::UpdateSymbolInstances(
         wxString path = symbolInstances[i].GetPath();
 
         auto it = std::find_if( aSymbolInstances.begin(), aSymbolInstances.end(),
-                                [ path, &getName ]( const COMPONENT_INSTANCE_REFERENCE& r ) -> bool
+                                [ path, &getName ]( const SYMBOL_INSTANCE_REFERENCE& r ) -> bool
                                 {
                                     return path == getName( r.m_Path );
                                 } );
diff --git a/eeschema/sch_sheet_path.h b/eeschema/sch_sheet_path.h
index 2d3347800c..0cecc5711b 100644
--- a/eeschema/sch_sheet_path.h
+++ b/eeschema/sch_sheet_path.h
@@ -40,7 +40,7 @@
 /**
  * A simple container for schematic symbol instance infromation.
  */
-struct COMPONENT_INSTANCE_REFERENCE
+struct SYMBOL_INSTANCE_REFERENCE
 {
     KIID_PATH m_Path;
 
@@ -68,45 +68,38 @@ struct SCH_SHEET_INSTANCE
 /**
  * Complex hierarchies
  *
- * A hierarchical schematic uses sheets (hierarchical sheets) included in a
- * given sheet.  Each sheet corresponds to a schematic drawing handled by a
- * SCH_SCREEN structure.  A SCH_SCREEN structure contains drawings, and have
- * a filename to write it's data.  Also a SCH_SCREEN display a sheet number
- * and the name of the sheet.
+ * A hierarchical schematic uses sheets (hierarchical sheets) included in a given sheet.
+ * Each sheet corresponds to a schematic drawing handled by a SCH_SCREEN structure.  A
+ * SCH_SCREEN structure contains drawings, and have a filename to write it's data.  Also a
+ * SCH_SCREEN displays a sheet number and the name of the sheet.
  *
- * In simple (and flat) hierarchies a sheet is linked to a SCH_SCREEN,
- * and a SCH_SCREEN is used by only one hierarchical sheet.
+ * In simple (and flat) hierarchies a sheet is linked to a SCH_SCREEN, and a SCH_SCREEN is
+ * used by the single hierarchical sheet.
  *
- * In complex hierarchies the same SCH_SCREEN (and its data) is shared between
- * more than one sheet.  Therefore subsheets (like subsheets in a SCH_SCREEN
- * shared by many sheets) can be also shared.  So the same SCH_SCREEN must
- * handle different components references and parts selection depending on
- * which sheet is currently selected, and how a given subsheet is selected.
- * 2 sheets share the same SCH_SCREEN (the same drawings) if they have the
- * same filename.
+ * In complex hierarchies the same SCH_SCREEN (and its data) is shared by more than one sheet.
+ * Therefore subsheets (like subsheets in a SCH_SCREEN shared by many sheets) can also be
+ * shared. So the same SCH_SCREEN must handle different symbol references and unit selections
+ * depending on which sheet is currently selected, and how a given subsheet is selected. Two
+ * sheets share the same SCH_SCREEN (the same drawings) if they have the same filename.
  *
- * In KiCad each component and sheet receives (when created) an unique
- * identification called Time Stamp.  So each sheet has 2 ids: its time stamp
- * (that cannot change) and its name ( that can be edited and therefore is
- * not reliable for strong identification).  KiCad uses Time Stamp ( a unique
- * 32 bit id), to identify sheets in hierarchies.
- * A given sheet in a hierarchy is fully labeled by its path (or sheet path)
- * that is the list of time stamp found to access it through the hierarchy
- * the root sheet is /.  All  other sheets have a path like /1234ABCD or
- * /4567FEDC/AA2233DD/.  This path can be displayed as human readable sheet
- * name like: / or /sheet1/include_sheet/ or /sheet2/include_sheet/
+ * In KiCad each symbol and sheet receives (when created) a uuid.  So each sheet has 2 id: its
+ * uuid (which cannot change) and its name (that can be edited and therefore is not reliable
+ * for strong identification).
+ * A given sheet in a hierarchy is fully labeled by its path (or sheet path) that is the list
+ * of uuids found to access it through the hierarchy.  The root sheet is /.  All  other sheets
+ * have a path like /1234ABCD or /4567FEDC/AA2233DD/.  This path can be displayed as human
+ * readable sheet name like: / or /sheet1/include_sheet/ or /sheet2/include_sheet/
  *
  * So to know for a given SCH_SCREEN (a given schematic drawings) we must:
  *   1) Handle all references possibilities.
  *   2) When acceded by a given selected sheet, display (update) the
  *      corresponding references and sheet path
  *
- * The class SCH_SHEET_PATH handles paths used to access a sheet.  The class
- * SCH_SHEET_LIST allows one to handle the full (or partial) list of sheets and
- * their paths in a complex hierarchy.  The class EDA_ScreenList allows one
- * to handle the list of SCH_SCREEN. It is useful to clear or save data,
- * but is not suitable to handle the full complex hierarchy possibilities
- * (usable in flat and simple hierarchies).
+ * The class SCH_SHEET_PATH handles paths used to access a sheet.  The class SCH_SHEET_LIST
+ * allows one to handle the full (or partial) list of sheets and their paths in a complex
+ * hierarchy.  The class EDA_ScreenList allows one to handle the list of SCH_SCREEN. It is
+ * useful  to clear or save data, but is not suitable to handle the full complex hierarchy
+ * possibilities (usable in flat and simple hierarchies).
  */
 
 
@@ -457,7 +450,7 @@ public:
      * WARNING: Do not call this on anything other than the full hierarchy.
      * @param aSymbolInstances is the symbol path information loaded from the root schematic.
      */
-    void UpdateSymbolInstances( const std::vector<COMPONENT_INSTANCE_REFERENCE>& aSymbolInstances );
+    void UpdateSymbolInstances( const std::vector<SYMBOL_INSTANCE_REFERENCE>& aSymbolInstances );
 
     /**
      * Update all of the sheet instance information using \a aSheetInstances.
diff --git a/eeschema/sch_text.h b/eeschema/sch_text.h
index f8dd640fec..281c3bd364 100644
--- a/eeschema/sch_text.h
+++ b/eeschema/sch_text.h
@@ -425,10 +425,17 @@ public:
     wxPoint GetIrefSavedPosition() { return m_savedIrefPos; }
     void SetIrefSavedPosition( wxPoint pos ) { m_savedIrefPos = pos; }
 
-    bool IsPointClickableAnchor( const wxPoint& aPos ) const override { return m_isDangling && GetPosition() == aPos; }
+    bool IsPointClickableAnchor( const wxPoint& aPos ) const override
+    {
+        return m_isDangling && GetPosition() == aPos;
+    }
 
 private:
-    bool doIsConnected( const wxPoint& aPosition ) const override { return EDA_TEXT::GetTextPos() == aPosition; }
+    bool doIsConnected( const wxPoint& aPosition ) const override
+    {
+        return EDA_TEXT::GetTextPos() == aPosition;
+    }
+
     SCH_IREF* m_iref;
     wxPoint   m_savedIrefPos;
 };
diff --git a/pcbnew/pcb_shape.h b/pcbnew/pcb_shape.h
index bc8f355105..014cb1e7c3 100644
--- a/pcbnew/pcb_shape.h
+++ b/pcbnew/pcb_shape.h
@@ -105,11 +105,10 @@ public:
         case S_SEGMENT:
         case S_ARC:
         case S_CURVE:
-        case S_LAST:        // Make CLang compiler happy
             return false;
 
-        case S_LAST:    // Sentinel
-            break;
+        case S_LAST:        // Make CLang compiler happy
+            return false;
         }
 
         return false;       // Make GCC compiler happy
diff --git a/qa/eeschema/test_sch_sheet.cpp b/qa/eeschema/test_sch_sheet.cpp
index a36745adc6..775b6b77f0 100644
--- a/qa/eeschema/test_sch_sheet.cpp
+++ b/qa/eeschema/test_sch_sheet.cpp
@@ -85,7 +85,7 @@ BOOST_AUTO_TEST_CASE( Default )
 
     BOOST_CHECK_EQUAL( m_csheet.GetScreenCount(), 0 );
 
-    BOOST_CHECK_EQUAL( m_sheet.ComponentCount(), 0 );
+    BOOST_CHECK_EQUAL( m_sheet.SymbolCount(), 0 );
 }
 
 /**