diff --git a/eeschema/dialogs/panel_eeschema_editing_options_base.cpp b/eeschema/dialogs/panel_eeschema_editing_options_base.cpp
index 17cbaa1d97..a326b8009c 100644
--- a/eeschema/dialogs/panel_eeschema_editing_options_base.cpp
+++ b/eeschema/dialogs/panel_eeschema_editing_options_base.cpp
@@ -105,7 +105,7 @@ PANEL_EESCHEMA_EDITING_OPTIONS_BASE::PANEL_EESCHEMA_EDITING_OPTIONS_BASE( wxWind
 	m_staticText101->Wrap( -1 );
 	fgSizerCmdsWinLin->Add( m_staticText101, 0, wxALL, 5 );
 
-	m_staticText131 = new wxStaticText( m_mouseCmdsWinLin->GetStaticBox(), wxID_ANY, _("Ctrl"), wxDefaultPosition, wxDefaultSize, 0 );
+	m_staticText131 = new wxStaticText( m_mouseCmdsWinLin->GetStaticBox(), wxID_ANY, _("Alt"), wxDefaultPosition, wxDefaultSize, 0 );
 	m_staticText131->Wrap( -1 );
 	fgSizerCmdsWinLin->Add( m_staticText131, 0, wxALL, 5 );
 
@@ -113,7 +113,7 @@ PANEL_EESCHEMA_EDITING_OPTIONS_BASE::PANEL_EESCHEMA_EDITING_OPTIONS_BASE( wxWind
 	m_staticText141->Wrap( -1 );
 	fgSizerCmdsWinLin->Add( m_staticText141, 0, wxALL, 5 );
 
-	m_staticText151 = new wxStaticText( m_mouseCmdsWinLin->GetStaticBox(), wxID_ANY, _("Ctrl+Shift"), wxDefaultPosition, wxDefaultSize, 0 );
+	m_staticText151 = new wxStaticText( m_mouseCmdsWinLin->GetStaticBox(), wxID_ANY, _("Alt+Shift"), wxDefaultPosition, wxDefaultSize, 0 );
 	m_staticText151->Wrap( -1 );
 	fgSizerCmdsWinLin->Add( m_staticText151, 0, wxALL, 5 );
 
@@ -121,7 +121,7 @@ PANEL_EESCHEMA_EDITING_OPTIONS_BASE::PANEL_EESCHEMA_EDITING_OPTIONS_BASE( wxWind
 	m_staticText161->Wrap( -1 );
 	fgSizerCmdsWinLin->Add( m_staticText161, 0, wxALL, 5 );
 
-	m_staticText111 = new wxStaticText( m_mouseCmdsWinLin->GetStaticBox(), wxID_ANY, _("Alt"), wxDefaultPosition, wxDefaultSize, 0 );
+	m_staticText111 = new wxStaticText( m_mouseCmdsWinLin->GetStaticBox(), wxID_ANY, _("Ctrl"), wxDefaultPosition, wxDefaultSize, 0 );
 	m_staticText111->Wrap( -1 );
 	fgSizerCmdsWinLin->Add( m_staticText111, 0, wxALL, 5 );
 
diff --git a/eeschema/dialogs/panel_eeschema_editing_options_base.fbp b/eeschema/dialogs/panel_eeschema_editing_options_base.fbp
index 6fa9ea1ed6..00d9c56b1d 100644
--- a/eeschema/dialogs/panel_eeschema_editing_options_base.fbp
+++ b/eeschema/dialogs/panel_eeschema_editing_options_base.fbp
@@ -43,7 +43,7 @@
             <property name="minimum_size"></property>
             <property name="name">PANEL_EESCHEMA_EDITING_OPTIONS_BASE</property>
             <property name="pos"></property>
-            <property name="size">661,584</property>
+            <property name="size">661,649</property>
             <property name="subclass">; forward_declare</property>
             <property name="tooltip"></property>
             <property name="window_extra_style"></property>
@@ -929,7 +929,7 @@
                                                 <property name="gripper">0</property>
                                                 <property name="hidden">0</property>
                                                 <property name="id">wxID_ANY</property>
-                                                <property name="label">Ctrl</property>
+                                                <property name="label">Alt</property>
                                                 <property name="markup">0</property>
                                                 <property name="max_size"></property>
                                                 <property name="maximize_button">0</property>
@@ -1051,7 +1051,7 @@
                                                 <property name="gripper">0</property>
                                                 <property name="hidden">0</property>
                                                 <property name="id">wxID_ANY</property>
-                                                <property name="label">Ctrl+Shift</property>
+                                                <property name="label">Alt+Shift</property>
                                                 <property name="markup">0</property>
                                                 <property name="max_size"></property>
                                                 <property name="maximize_button">0</property>
@@ -1173,7 +1173,7 @@
                                                 <property name="gripper">0</property>
                                                 <property name="hidden">0</property>
                                                 <property name="id">wxID_ANY</property>
-                                                <property name="label">Alt</property>
+                                                <property name="label">Ctrl</property>
                                                 <property name="markup">0</property>
                                                 <property name="max_size"></property>
                                                 <property name="maximize_button">0</property>
diff --git a/eeschema/dialogs/panel_eeschema_editing_options_base.h b/eeschema/dialogs/panel_eeschema_editing_options_base.h
index 9507d4cdea..bf33b43060 100644
--- a/eeschema/dialogs/panel_eeschema_editing_options_base.h
+++ b/eeschema/dialogs/panel_eeschema_editing_options_base.h
@@ -80,7 +80,7 @@ class PANEL_EESCHEMA_EDITING_OPTIONS_BASE : public wxPanel
 
 	public:
 
-		PANEL_EESCHEMA_EDITING_OPTIONS_BASE( wxWindow* parent, wxWindowID id = wxID_ANY, const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxSize( 661,584 ), long style = wxTAB_TRAVERSAL, const wxString& name = wxEmptyString );
+		PANEL_EESCHEMA_EDITING_OPTIONS_BASE( wxWindow* parent, wxWindowID id = wxID_ANY, const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxSize( 661,649 ), long style = wxTAB_TRAVERSAL, const wxString& name = wxEmptyString );
 		~PANEL_EESCHEMA_EDITING_OPTIONS_BASE();
 
 };
diff --git a/eeschema/tools/ee_selection_tool.cpp b/eeschema/tools/ee_selection_tool.cpp
index 2e64e42cd3..0f462a898c 100644
--- a/eeschema/tools/ee_selection_tool.cpp
+++ b/eeschema/tools/ee_selection_tool.cpp
@@ -324,22 +324,73 @@ int EE_SELECTION_TOOL::Main( const TOOL_EVENT& aEvent )
         bool displayBusCursor = false;
         bool displayLineCursor = false;
         KIID rolloverItem = lastRolloverItem;
-        m_additive = m_subtractive = m_exclusive_or = false;
 
-        if( evt->Modifier( MD_SHIFT ) && evt->Modifier( MD_CTRL ) )
-            m_subtractive = true;
-        else if( evt->Modifier( MD_SHIFT ) )
-            m_additive = true;
-        else if( evt->Modifier( MD_CTRL ) )
-            m_exclusive_or = true;
+        // on left click, a selection is made, depending on modifiers ALT, SHIFT, CTRL:
+        // Due to the fact ALT key modifier cannot be useed freely on Winows and Linux,
+        // actions are different on OSX and others OS
+        // Especially, ALT key cannot be used to force showing the full selection choice
+        // context menu (the menu is immediately closed on Windows )
+        //
+        // No modifier = select items and deselect previous selection
+        // ALT (on OSX) = skip heuristic and show full selection choice
+        // ALT (on others) = exclusive OR of selected items (inverse selection)
+        //
+        // CTRL/CMD (on OSX) = exclusive OR of selected items (inverse selection)
+        // CTRL (on others) = skip heuristic and show full selection choice
+        //
+        // SHIFT = add selected items to the current selection
+        //
+        // CTRL/CMD+SHIFT (on OSX) = remove selected items to the current selection
+        // CTRL+SHIFT (on others) = unused (can be used for a new action)
+        //
+        // CTRL/CMT+ALT (on OSX) = unused (can be used for a new action)
+        // CTRL+ALT (on others) = do nothing (same as no modifier)
+        //
+        // SHIFT+ALT (on OSX) =  do nothing (same as no modifier)
+        // SHIFT+ALT (on others) = remove selected items to the current selection
 
-        bool              modifier_enabled = m_subtractive || m_additive || m_exclusive_or;
-        MOUSE_DRAG_ACTION drag_action = m_frame->GetDragAction();
+#ifdef __WXOSX_MAC__
+        m_subtractive = evt->Modifier( MD_CTRL ) &&
+                        evt->Modifier( MD_SHIFT ) &&
+                        !evt->Modifier( MD_ALT );
+
+        m_additive = evt->Modifier( MD_SHIFT ) &&
+                     !evt->Modifier( MD_CTRL ) &&
+                     !evt->Modifier( MD_ALT );
+
+        m_exclusive_or = evt->Modifier( MD_CTRL ) &&
+                         !evt->Modifier( MD_SHIFT ) &&
+                         !evt->Modifier( MD_ALT );
+
+        m_skip_heuristics = evt->Modifier( MD_ALT ) &&
+                            !evt->Modifier( MD_SHIFT ) &&
+                            !evt->Modifier( MD_CTRL );
+
+#else
+        m_subtractive = evt->Modifier( MD_SHIFT )
+                        && !evt->Modifier( MD_CTRL )
+                        && evt->Modifier( MD_ALT );
+
+        m_additive = evt->Modifier( MD_SHIFT )
+                     && !evt->Modifier( MD_CTRL )
+                     && !evt->Modifier( MD_ALT );
+
+        m_exclusive_or = !evt->Modifier( MD_SHIFT )
+                         && !evt->Modifier( MD_CTRL )
+                         && evt->Modifier( MD_ALT );
 
         // Is the user requesting that the selection list include all possible
         // items without removing less likely selection candidates
-        m_skip_heuristics = !!evt->Modifier( MD_ALT );
+        // Cannot use the Alt key on windows or the disambiguation context menu is immediately
+        // dismissed rendering it useless.
+        m_skip_heuristics = evt->Modifier( MD_CTRL )
+                            && !evt->Modifier( MD_SHIFT )
+                            && !evt->Modifier( MD_ALT );
+#endif
 
+        bool modifier_enabled = m_subtractive || m_additive || m_exclusive_or;
+
+        MOUSE_DRAG_ACTION drag_action = m_frame->GetDragAction();
         EE_GRID_HELPER grid( m_toolMgr );
 
         // Single click? Select single object
diff --git a/pagelayout_editor/dialogs/properties_frame_base.fbp b/pagelayout_editor/dialogs/properties_frame_base.fbp
index 571fef90bb..a1cffe9e11 100644
--- a/pagelayout_editor/dialogs/properties_frame_base.fbp
+++ b/pagelayout_editor/dialogs/properties_frame_base.fbp
@@ -14,10 +14,9 @@
         <property name="file">properties_frame_base</property>
         <property name="first_id">1000</property>
         <property name="help_provider">none</property>
-        <property name="image_path_wrapper_function_name"></property>
         <property name="indent_with_spaces"></property>
         <property name="internationalize">1</property>
-        <property name="name">properties_frame</property>
+        <property name="name">properties_frame_base</property>
         <property name="namespace"></property>
         <property name="path">.</property>
         <property name="precompiled_header"></property>
@@ -26,7 +25,6 @@
         <property name="skip_php_events">1</property>
         <property name="skip_python_events">1</property>
         <property name="ui_table">UI</property>
-        <property name="use_array_enum">0</property>
         <property name="use_enum">1</property>
         <property name="use_microsoft_bom">0</property>
         <object class="Panel" expanded="1">
@@ -45,7 +43,7 @@
             <property name="minimum_size"></property>
             <property name="name">PANEL_PROPERTIES_BASE</property>
             <property name="pos"></property>
-            <property name="size">-1,-1</property>
+            <property name="size">309,888</property>
             <property name="subclass"></property>
             <property name="tooltip"></property>
             <property name="window_extra_style"></property>
@@ -4016,7 +4014,6 @@
                                             <property name="aui_name"></property>
                                             <property name="aui_position"></property>
                                             <property name="aui_row"></property>
-                                            <property name="auth_needed">0</property>
                                             <property name="best_size"></property>
                                             <property name="bg"></property>
                                             <property name="bitmap"></property>
@@ -4979,7 +4976,6 @@
                                                     <property name="aui_name"></property>
                                                     <property name="aui_position"></property>
                                                     <property name="aui_row"></property>
-                                                    <property name="auth_needed">0</property>
                                                     <property name="best_size"></property>
                                                     <property name="bg"></property>
                                                     <property name="bitmap"></property>
@@ -5869,7 +5865,6 @@
                                                     <property name="aui_name"></property>
                                                     <property name="aui_position"></property>
                                                     <property name="aui_row"></property>
-                                                    <property name="auth_needed">0</property>
                                                     <property name="best_size"></property>
                                                     <property name="bg"></property>
                                                     <property name="bitmap"></property>
diff --git a/pagelayout_editor/tools/pl_selection_tool.cpp b/pagelayout_editor/tools/pl_selection_tool.cpp
index 88766ad79f..c8c8695f3b 100644
--- a/pagelayout_editor/tools/pl_selection_tool.cpp
+++ b/pagelayout_editor/tools/pl_selection_tool.cpp
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2019 CERN
- * Copyright (C) 2019 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2021 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -106,20 +106,70 @@ int PL_SELECTION_TOOL::Main( const TOOL_EVENT& aEvent )
     // Main loop: keep receiving events
     while( TOOL_EVENT* evt = Wait() )
     {
-        m_additive = m_subtractive = m_exclusive_or = false;
+        // on left click, a selection is made, depending on modifiers ALT, SHIFT, CTRL:
+        // Due to the fact ALT key modifier cannot be useed freely on Winows and Linux,
+        // actions are different on OSX and others OS
+        // Especially, ALT key cannot be used to force showing the full selection choice
+        // context menu (the menu is immediately closed on Windows )
+        //
+        // No modifier = select items and deselect previous selection
+        // ALT (on OSX) = skip heuristic and show full selection choice
+        // ALT (on others) = exclusive OR of selected items (inverse selection)
+        //
+        // CTRL/CMD (on OSX) = exclusive OR of selected items (inverse selection)
+        // CTRL (on others) = skip heuristic and show full selection choice
+        //
+        // SHIFT = add selected items to the current selection
+        //
+        // CTRL/CMD+SHIFT (on OSX) = remove selected items to the current selection
+        // CTRL+SHIFT (on others) = unused (can be used for a new action)
+        //
+        // CTRL/CMT+ALT (on OSX) = unused (can be used for a new action)
+        // CTRL+ALT (on others) = do nothing (same as no modifier)
+        //
+        // SHIFT+ALT (on OSX) =  do nothing (same as no modifier)
+        // SHIFT+ALT (on others) = remove selected items to the current selection
 
-        if( evt->Modifier( MD_SHIFT ) && evt->Modifier( MD_CTRL ) )
-            m_subtractive = true;
-        else if( evt->Modifier( MD_SHIFT ) )
-            m_additive = true;
-        else if( evt->Modifier( MD_CTRL ) )
-            m_exclusive_or = true;
+#ifdef __WXOSX_MAC__
+        m_subtractive = evt->Modifier( MD_CTRL ) &&
+                        evt->Modifier( MD_SHIFT ) &&
+                        !evt->Modifier( MD_ALT );
 
-        bool modifier_enabled = m_subtractive || m_additive || m_exclusive_or;
+        m_additive = evt->Modifier( MD_SHIFT ) &&
+                     !evt->Modifier( MD_CTRL ) &&
+                     !evt->Modifier( MD_ALT );
+
+        m_exclusive_or = evt->Modifier( MD_CTRL ) &&
+                         !evt->Modifier( MD_SHIFT ) &&
+                         !evt->Modifier( MD_ALT );
+
+        m_skip_heuristics = evt->Modifier( MD_ALT ) &&
+                            !evt->Modifier( MD_SHIFT ) &&
+                            !evt->Modifier( MD_CTRL );
+
+#else
+        m_subtractive = evt->Modifier( MD_SHIFT )
+                        && !evt->Modifier( MD_CTRL )
+                        && evt->Modifier( MD_ALT );
+
+        m_additive = evt->Modifier( MD_SHIFT )
+                     && !evt->Modifier( MD_CTRL )
+                     && !evt->Modifier( MD_ALT );
+
+        m_exclusive_or = !evt->Modifier( MD_SHIFT )
+                         && !evt->Modifier( MD_CTRL )
+                         && evt->Modifier( MD_ALT );
 
         // Is the user requesting that the selection list include all possible
         // items without removing less likely selection candidates
-        m_skip_heuristics = !!evt->Modifier( MD_ALT );
+        // Cannot use the Alt key on windows or the disambiguation context menu is immediately
+        // dismissed rendering it useless.
+        m_skip_heuristics = evt->Modifier( MD_CTRL )
+                            && !evt->Modifier( MD_SHIFT )
+                            && !evt->Modifier( MD_ALT );
+#endif
+
+        bool modifier_enabled = m_subtractive || m_additive || m_exclusive_or;
 
         // Single click? Select single object
         if( evt->IsClick( BUT_LEFT ) )