diff --git a/App.xaml b/App.xaml
index 4f1233e9c..99f73bace 100644
--- a/App.xaml
+++ b/App.xaml
@@ -273,7 +273,10 @@
         <!-- Operator-supplied glyphs. Wireless geometry remains GOOSE-specific. -->
         <Geometry x:Key="OperatorIecTopologyIcon">M600-160v-80H440v-200h-80v80H80v-240h280v80h80v-200h160v-80h280v240H600v-80h-80v320h80v-80h280v240H600Zm80-80h120v-80H680v80ZM160-440h120v-80H160v80Zm520-200h120v-80H680v80Zm0 400v-80 80ZM280-440v-80 80Zm400-200v-80 80Z</Geometry>
         <Geometry x:Key="OperatorDiagnosticsIcon">M80-600v-120q0-33 23.5-56.5T160-800h640q33 0 56.5 23.5T880-720v220h-80v-220H160v120H80Zm200 320q-11 0-21-5.5T244-302l-69-138H80v-80h120q11 0 21 5.5t15 16.5l44 88 124-248q5-10 15-15t21-5q11 0 21 5t15 15l67 134q-18 11-34.5 23T478-474l-38-76-124 248q-5 11-15 16.5t-21 5.5Zm147 120H160q-33 0-56.5-23.5T80-240v-120h80v120h243q3 21 9 41t15 39Zm53-320Zm58.5 341.5Q480-197 480-280t58.5-141.5Q597-480 680-480t141.5 58.5Q880-363 880-280t-58.5 141.5Q763-80 680-80t-141.5-58.5ZM688-260l91-91-28-28-91 91 28 28Z</Geometry>
-        <Geometry x:Key="OperatorCommandDockPowerIcon">M451.5-491.5Q440-503 440-520v-320q0-17 11.5-28.5T480-880q17 0 28.5 11.5T520-840v320q0 17-11.5 28.5T480-480q-17 0-28.5-11.5Zm-112 343q-65.5-28.5-114-77t-77-114Q120-405 120-480q0-61 20-118.5T198-704q11-14 28-13.5t30 13.5q11 11 10 27t-11 30q-27 36-41 79t-14 88q0 117 81.5 198.5T480-200q117 0 198.5-81.5T760-480q0-46-13.5-89.5T704-649q-10-13-11-28.5t10-26.5q12-12 29-12.5t28 12.5q39 48 59.5 105T840-480q0 75-28.5 140.5t-77 114q-48.5 48.5-114 77T480-120q-75 0-140.5-28.5Z</Geometry>
+        <Geometry x:Key="OperatorCommandDockPowerIcon">M324-111.5Q251-143 197-197t-85.5-127Q80-397 80-480t31.5-156Q143-709 197-763t127-85.5Q397-880 480-880t156 31.5Q709-817 763-763t85.5 127Q880-563 880-480t-31.5 156Q817-251 763-197t-127 85.5Q563-80 480-80t-156-31.5ZM707-253q93-93 93-227t-93-227q-93-93-227-93t-227 93q-93 93-93 227t93 227q93 93 227 93t227-93Zm-57-57q70-70 70-170 0-51-19-94.5T650-650l-57 57q22 22 34.5 51t12.5 62q0 66-47 113t-113 47q-66 0-113-47t-47-113q0-33 12.5-62t34.5-51l-57-57q-32 32-51 75.5T240-480q0 100 70 170t170 70q100 0 170-70ZM440-480h80v-240h-80v240Zm40 0Z</Geometry>
+        <!-- Source contours from operator SVGs (native WPF Geometry; no bitmap or runtime conversion). -->
+        <Geometry x:Key="OperatorCommandDockChevronDownIcon">m480-340 180-180-57-56-123 123-123-123-57 56 180 180Zm0 260q-83 0-156-31.5T197-197q-54-54-85.5-127T80-480q0-83 31.5-156T197-763q54-54 127-85.5T480-880q83 0 156 31.5T763-763q54 54 85.5 127T880-480q0 83-31.5 156T763-197q-54 54-127 85.5T480-80Zm0-80q134 0 227-93t93-227q0-134-93-227t-227-93q-134 0-227 93t-93 227q0 134 93 227t227 93Zm0-320Z</Geometry>
+        <Geometry x:Key="OperatorCommandDockChevronUpIcon">m357-384 123-123 123 123 57-56-180-180-180 180 57 56ZM480-80q-83 0-156-31.5T197-197q-54-54-85.5-127T80-480q0-83 31.5-156T197-763q54-54 127-85.5T480-880q83 0 156 31.5T763-763q54 54 85.5 127T880-480q0 83-31.5 156T763-197q-54 54-127 85.5T480-80Zm0-80q134 0 227-93t93-227q0-134-93-227t-227-93q-134 0-227 93t-93 227q0 134 93 227t227 93Zm0-320Z</Geometry>
         <!-- GOOSE wireless indicator remains unchanged. -->
         <Geometry x:Key="OperatorIecWirelessIcon">M280-200q-33 0-56.5-23.5T200-280v-400q0-33 23.5-56.5T280-760h400q33 0 56.5 23.5T760-680v400q0 33-23.5 56.5T680-200H280Zm0 80h400q66 0 113-47t47-113v-400q0-66-47-113t-113-47H280q-66 0-113 47t-47 113v400q0 66 47 113t113 47Zm11-379-55-55q42-51 108.5-78.5T480-660q67 0 134 27.5T723-554l-55 55q-35-38-83.5-59.5T480-580q-56 0-104.5 21.5T291-499Zm114 114-57-57q26-28 60.5-43t72.5-15q38 0 71.5 15t59.5 43l-56 57q-14-15-34.5-25T480-420q-21 0-41 10t-34 25Zm46.5 93.5Q440-303 440-320t11.5-28.5Q463-360 480-360t28.5 11.5Q520-337 520-320t-11.5 28.5Q497-280 480-280t-28.5-11.5ZM480-480Z</Geometry>
         <Geometry x:Key="OperatorLiveMonitorIcon">M308.5-411.5Q320-423 320-440t-11.5-28.5Q297-480 280-480t-28.5 11.5Q240-457 240-440t11.5 28.5Q263-400 280-400t28.5-11.5Zm0-160Q320-583 320-600t-11.5-28.5Q297-640 280-640t-28.5 11.5Q240-617 240-600t11.5 28.5Q263-560 280-560t28.5-11.5ZM360-400h360v-80H360v80Zm0-160h360v-80H360v80Zm-40 440v-80H160q-33 0-56.5-23.5T80-280v-480q0-33 23.5-56.5T160-840h640q33 0 56.5 23.5T880-760v480q0 33-23.5 56.5T800-200H640v80H320ZM160-280h640v-480H160v480Zm0 0v-480 480Z</Geometry>
@@ -673,6 +676,80 @@
             <Setter Property="MinWidth" Value="56"/>
         </Style>
 
+        <!-- P0 UI-only override: preserve the original Expander instance, handlers, data grid,
+             and content. The native chevron chrome is replaced by the exact operator SVG glyphs. -->
+        <Style x:Key="CommandDockTransparentHeaderExpander" TargetType="{x:Type Expander}">
+            <Setter Property="Foreground" Value="White"/>
+            <Setter Property="Background" Value="Transparent"/>
+            <Setter Property="BorderBrush" Value="Transparent"/>
+            <Setter Property="BorderThickness" Value="0"/>
+            <Setter Property="Template">
+                <Setter.Value>
+                    <ControlTemplate TargetType="{x:Type Expander}">
+                        <Grid Background="Transparent" SnapsToDevicePixels="True">
+                            <Grid.RowDefinitions>
+                                <RowDefinition Height="Auto"/>
+                                <RowDefinition Height="Auto"/>
+                            </Grid.RowDefinitions>
+                            <ToggleButton x:Name="CommandDockHeaderToggle" Grid.Row="0"
+                                          Content="{TemplateBinding Header}"
+                                          Background="Transparent" BorderBrush="Transparent" BorderThickness="0"
+                                          Padding="0" Cursor="Hand" Focusable="True"
+                                          AutomationProperties.Name="Expand or collapse Command Dock"
+                                          IsChecked="{Binding IsExpanded, RelativeSource={RelativeSource TemplatedParent}, Mode=TwoWay}">
+                                <ToggleButton.Template>
+                                    <ControlTemplate TargetType="{x:Type ToggleButton}">
+                                        <Border x:Name="HeaderFocusRing" Background="Transparent"
+                                                BorderBrush="Transparent" BorderThickness="1" CornerRadius="4">
+                                            <Grid Background="Transparent" MinHeight="28">
+                                                <Grid.ColumnDefinitions>
+                                                    <ColumnDefinition Width="25"/>
+                                                    <ColumnDefinition Width="*"/>
+                                                </Grid.ColumnDefinitions>
+                                                <Grid Grid.Column="0" Width="19" Height="19"
+                                                      HorizontalAlignment="Left" VerticalAlignment="Center">
+                                                    <Viewbox x:Name="ChevronCollapsed" Width="19" Height="19">
+                                                        <Path Data="{StaticResource OperatorCommandDockChevronDownIcon}"
+                                                              Fill="White" Stretch="Uniform"/>
+                                                    </Viewbox>
+                                                    <Viewbox x:Name="ChevronExpanded" Width="19" Height="19"
+                                                             Visibility="Collapsed">
+                                                        <Path Data="{StaticResource OperatorCommandDockChevronUpIcon}"
+                                                              Fill="White" Stretch="Uniform"/>
+                                                    </Viewbox>
+                                                </Grid>
+                                                <ContentPresenter Grid.Column="1" ContentSource="Content"
+                                                                  HorizontalAlignment="Left" VerticalAlignment="Center"/>
+                                            </Grid>
+                                        </Border>
+                                        <ControlTemplate.Triggers>
+                                            <Trigger Property="IsChecked" Value="True">
+                                                <Setter TargetName="ChevronCollapsed" Property="Visibility" Value="Collapsed"/>
+                                                <Setter TargetName="ChevronExpanded" Property="Visibility" Value="Visible"/>
+                                            </Trigger>
+                                            <Trigger Property="IsMouseOver" Value="True">
+                                                <Setter Property="Opacity" Value="0.93"/>
+                                            </Trigger>
+                                            <Trigger Property="IsKeyboardFocused" Value="True">
+                                                <Setter TargetName="HeaderFocusRing" Property="BorderBrush" Value="#AAFFFFFF"/>
+                                            </Trigger>
+                                        </ControlTemplate.Triggers>
+                                    </ControlTemplate>
+                                </ToggleButton.Template>
+                            </ToggleButton>
+                            <ContentPresenter x:Name="CommandDockContentHost" Grid.Row="1"
+                                              ContentSource="Content" Visibility="Collapsed"/>
+                        </Grid>
+                        <ControlTemplate.Triggers>
+                            <Trigger Property="IsExpanded" Value="True">
+                                <Setter TargetName="CommandDockContentHost" Property="Visibility" Value="Visible"/>
+                            </Trigger>
+                        </ControlTemplate.Triggers>
+                    </ControlTemplate>
+                </Setter.Value>
+            </Setter>
+        </Style>
+
         <Style x:Key="CommandDockPrimaryButton" TargetType="Button" BasedOn="{StaticResource CommandActionButtonBase}">
             <Setter Property="Background" Value="{StaticResource AccentGradient}"/>
             <Setter Property="BorderBrush" Value="#4B83DF"/>
diff --git a/MainWindow.xaml b/MainWindow.xaml
index 3bd82dad0..91c1b11aa 100644
--- a/MainWindow.xaml
+++ b/MainWindow.xaml
@@ -692,15 +692,19 @@
                             </Border>
 
                             <Expander x:Name="CommandPanelExpander" Grid.Row="1" Margin="0,10,0,0" IsExpanded="False"
+                                      Style="{StaticResource CommandDockTransparentHeaderExpander}"
                                       VerticalAlignment="Stretch" Expanded="CommandPanel_Expanded" Collapsed="CommandPanel_Collapsed">
                                 <Expander.Header>
                                     <StackPanel Orientation="Horizontal" VerticalAlignment="Center">
-                                        <Border Width="28" Height="28" CornerRadius="9" Background="#E7F0FF" BorderBrush="#C9DBF7" BorderThickness="1" Margin="0,0,9,0">
-                                            <Viewbox Width="15" Height="15" HorizontalAlignment="Center" VerticalAlignment="Center">
-                                                <Path Data="{StaticResource OperatorCommandDockPowerIcon}" Style="{StaticResource MaterialIconGlyph}"/>
-                                            </Viewbox>
-                                        </Border>
-                                        <TextBlock Text="IED Command Panel" FontSize="13.6" FontWeight="SemiBold" Foreground="{StaticResource Ink}" VerticalAlignment="Center"/>
+                                        <!-- Power is header iconography, not a second control or a raised card.
+                                             The entire transparent header remains the one keyboard/mouse toggle. -->
+                                        <Viewbox Width="19" Height="19" Margin="0,0,7,0"
+                                                 HorizontalAlignment="Center" VerticalAlignment="Center">
+                                            <Path Data="{StaticResource OperatorCommandDockPowerIcon}"
+                                                  Fill="White" Stretch="Uniform"/>
+                                        </Viewbox>
+                                        <TextBlock Text="IED Command Panel" FontSize="13.6" FontWeight="SemiBold"
+                                                   Foreground="White" VerticalAlignment="Center"/>
                                     </StackPanel>
                                 </Expander.Header>
                                 <Border Style="{StaticResource WorkspaceCard}" Background="{StaticResource CommandPanelSurface}" Padding="6" BorderBrush="#BFD0E5">
diff --git a/docs/CHECKPOINT_COMMAND_DOCK_FAT_UI_PHASE1_2026-10-20.md b/docs/CHECKPOINT_COMMAND_DOCK_FAT_UI_PHASE1_2026-10-20.md
new file mode 100644
index 000000000..b1f89a976
--- /dev/null
+++ b/docs/CHECKPOINT_COMMAND_DOCK_FAT_UI_PHASE1_2026-10-20.md
@@ -0,0 +1,34 @@
+# ARSAS Command Dock FAT — frozen checkpoint and P0 UI Phase 1
+
+**Date:** 2026-10-20 · **Owner scope:** Command Dock header cosmetics only.
+
+## Frozen source checkpoints (do not force-update/rebase)
+
+| Type | Branch | Full SHA | Evidence |
+| --- | --- | --- | --- |
+| Exact-SHA Windows FAT / native bridge | `checkpoint/arsas-fat-green-20261020` | `30a7f18e8e575604eb1306c96753daab9f9c4a51` | GitHub Actions `39404069355`; all 11 CI workflows succeeded; 2,409 consumer + 24 pinned engine + 6 packaged regression tests passed; portable EXE smoke test passed. |
+| User-tested field software | `checkpoint/arsas-field-command-stable-20261020` | `de71a1a45c30d0221766c389d96553e051b20c17` | Screenshot and diagnostic at 2026-10-20 17:40 +07; Git source tree byte-for-byte identical to green FAT commit (compare shows no changed files); user reports stable grid and command improvement. |
+
+The field SHA has the tested FAT SHA as a merge parent, but its **own separate CI run was not recorded**. Do not claim separate field-SHA CI or a complete relay FAT. Engine exact SHA: `c85d4e20db722bd0c2729f2533b323b13d3ef735`.
+
+Field command diagnostic demonstrates *positive* SBOw, Operate, CommandTermination and confirmed process feedback for real commands. Example click-to-result ~414–461 ms, with a ~399–404 ms local post-SBOw-response wait; this is **not** interpreted as physical IED CommandTermination latency or on-wire RTT. Repeated already-at-state requests were reported `NotSent` (no control wire requests), as required.
+
+## Phase 1 — strict UI-only changes
+
+- Add exact filled SVG contours for chevron down/up and power as static WPF Geometry resources.
+- Scope a transparent, white-glyph Expander header template **only** to `CommandPanelExpander`; one accessible keyboard/mouse ToggleButton controls original `IsExpanded` property and original ContentPresenter.
+- Remove the colored power card, border and blue badge; render power as white glyph beside white `Command Dock` label.
+- Keep dark header surface, target badge, DataGrid instances, persistent workspace lifetime, handlers, and all control authorization and wire code unchanged.
+- Use template-triggered instant chevron reversal; no timers, animations, icon downloads, image files or extra commands.
+- Source contract regression `P109XCommandDockWhiteGlyphRegressionTests`: exact SVG geometry, transparent scope, keyboard toggle, collapsed/expanded content, no command handler or data grid loss.
+
+## Release / acceptance gates
+
+1. Require exact-head Windows CI green, all packed/native smoke regression checks, and downloadable portable artifact for the icon PR.
+2. Visual FAT on 100% and 150% DPI: glyphs white and aligned, no power bubble, chevron down when collapsed and up when expanded, full header target badge remains intact.
+3. Confirm keyboard Space activation, navigation Explorer -> Browser -> Diagnostics -> Explorer, no flicker and no newly queued MMS work from expand/collapse.
+4. Validate no negative change to previously proven command response stages. Do not send unnecessary commands to energized equipment.
+
+**Deferred Phase 2 (out of scope):** redesign discovery progress to a fixed under-IP thin line rather than a separate empty animation card. Follow-up must reuse existing per-IED activity progress authority instead of creating another progress SSOT.
+
+**Do not merge into main/release on CI alone.** This PR is an isolated visual trial based on a frozen field checkpoint.
diff --git a/tests/ARSAS.Tests/MaterialIconConsistencyTests.cs b/tests/ARSAS.Tests/MaterialIconConsistencyTests.cs
index 072d75def..4291628ff 100644
--- a/tests/ARSAS.Tests/MaterialIconConsistencyTests.cs
+++ b/tests/ARSAS.Tests/MaterialIconConsistencyTests.cs
@@ -53,7 +53,7 @@ public void SelectedOperatorPathsBindToExactlyOneNavigationAndCommandGlyph()
         {
             ("OperatorIecTopologyIcon", "M600-160v-80"),
             ("OperatorDiagnosticsIcon", "M80-600v-120"),
-            ("OperatorCommandDockPowerIcon", "M451.5-491.5")
+            ("OperatorCommandDockPowerIcon", "M324-111.5")
         })
         {
             var entry = Assert.Single(app.Descendants(P + "Geometry"), g =>
@@ -61,6 +61,19 @@ public void SelectedOperatorPathsBindToExactlyOneNavigationAndCommandGlyph()
             Assert.StartsWith(prefix, entry.Value);
             Assert.False(Geometry.Parse(entry.Value).Bounds.IsEmpty);
         }
+        // Phase 1 freezes the complete up/down icons supplied by the operator.
+        // They must remain valid nonempty WPF paths at any display DPI.
+        foreach (var key in new[]
+        {
+            "OperatorCommandDockChevronDownIcon",
+            "OperatorCommandDockChevronUpIcon"
+        })
+        {
+            var entry = Assert.Single(app.Descendants(P + "Geometry"), g =>
+                (string?)g.Attribute(X + "Key") == key);
+            Assert.False(Geometry.Parse(entry.Value).Bounds.IsEmpty);
+        }
+
         var command = Assert.Single(xaml.Descendants(P + "Expander"),
             x => (string?)x.Attribute(X + "Name") == "CommandPanelExpander");
         Assert.Equal("{StaticResource OperatorCommandDockPowerIcon}",
diff --git a/tests/ARSAS.Tests/P109XCommandDockWhiteGlyphRegressionTests.cs b/tests/ARSAS.Tests/P109XCommandDockWhiteGlyphRegressionTests.cs
new file mode 100644
index 000000000..802550c69
--- /dev/null
+++ b/tests/ARSAS.Tests/P109XCommandDockWhiteGlyphRegressionTests.cs
@@ -0,0 +1,111 @@
+using System.Xml.Linq;
+
+namespace ARSAS.Tests;
+
+/// <summary>
+/// P0 cosmetic-only checkpoint: replacing Command Dock chrome must not
+/// change MMS command admission, DataGrid row lifetime or other expanders.
+/// </summary>
+public sealed class P109XCommandDockWhiteGlyphRegressionTests
+{
+    private static string Source(string path)
+    {
+        var dir = new DirectoryInfo(AppContext.BaseDirectory);
+        while (dir != null)
+        {
+            var candidate = Path.Combine(dir.FullName, path);
+            if (File.Exists(candidate))
+                return File.ReadAllText(candidate);
+            dir = dir.Parent;
+        }
+
+        throw new FileNotFoundException(path);
+    }
+
+    private static readonly XNamespace Presentation = "http://schemas.microsoft.com/winfx/2006/xaml/presentation";
+    private static readonly XNamespace Xaml = "http://schemas.microsoft.com/winfx/2006/xaml";
+
+    [Fact]
+    public void OperatorContoursRemainExactAndWhiteWithTransparentChrome()
+    {
+        var app = XDocument.Parse(Source("App.xaml"));
+        string Geometry(string key) => app.Descendants(Presentation + "Geometry")
+            .Single(node => (string?)node.Attribute(Xaml + "Key") == key).Value.Trim();
+
+        Assert.StartsWith(
+            "m480-340 180-180-57-56-123 123-123-123-57 56 180 180Zm0 260",
+            Geometry("OperatorCommandDockChevronDownIcon"), StringComparison.Ordinal);
+        Assert.StartsWith("m357-384 123-123 123 123 57-56", Geometry("OperatorCommandDockChevronUpIcon"), StringComparison.Ordinal);
+        Assert.StartsWith("M324-111.5Q251-143 197-197", Geometry("OperatorCommandDockPowerIcon"), StringComparison.Ordinal);
+        var style = app.Descendants(Presentation + "Style")
+            .Single(node => (string?)node.Attribute(Xaml + "Key") == "CommandDockTransparentHeaderExpander");
+        Assert.Equal("{x:Type Expander}", (string?)style.Attribute("TargetType"));
+        Assert.Contains(style.Descendants(Presentation + "Setter"),
+            s => (string?)s.Attribute("Property") == "Background" &&
+                 (string?)s.Attribute("Value") == "Transparent");
+
+        var paths = style.Descendants(Presentation + "Path").ToArray();
+        Assert.Equal(2, paths.Length);
+        Assert.All(paths, path => Assert.Equal("White", (string?)path.Attribute("Fill")));
+        Assert.Contains(paths, p => (string?)p.Attribute("Data") == "{StaticResource OperatorCommandDockChevronDownIcon}");
+        Assert.Contains(paths, p => (string?)p.Attribute("Data") == "{StaticResource OperatorCommandDockChevronUpIcon}");
+    }
+
+    [Fact]
+    public void OneExpanderKeepsKeyboardToggleAndContentVisibleOnlyWhenExpanded()
+    {
+        var app = XDocument.Parse(Source("App.xaml"));
+        var style = app.Descendants(Presentation + "Style")
+            .Single(node => (string?)node.Attribute(Xaml + "Key") == "CommandDockTransparentHeaderExpander");
+        var toggle = style.Descendants(Presentation + "ToggleButton")
+            .Single(node => (string?)node.Attribute(Xaml + "Name") == "CommandDockHeaderToggle");
+
+        Assert.Equal("{TemplateBinding Header}", (string?)toggle.Attribute("Content"));
+        Assert.Equal("{Binding IsExpanded, RelativeSource={RelativeSource TemplatedParent}, Mode=TwoWay}",
+            (string?)toggle.Attribute("IsChecked"));
+        Assert.Equal("True", (string?)toggle.Attribute("Focusable"));
+        Assert.Equal("Transparent", (string?)toggle.Attribute("Background"));
+        Assert.Contains(style.Descendants(Presentation + "Trigger"),
+            t => (string?)t.Attribute("Property") == "IsChecked" &&
+                 (string?)t.Attribute("Value") == "True");
+        Assert.Contains(style.Descendants(Presentation + "Trigger"),
+            t => (string?)t.Attribute("Property") == "IsExpanded" &&
+                 (string?)t.Attribute("Value") == "True" &&
+                 t.Descendants(Presentation + "Setter").Any(s =>
+                     (string?)s.Attribute("TargetName") == "CommandDockContentHost" &&
+                     (string?)s.Attribute("Value") == "Visible"));
+
+        var host = style.Descendants(Presentation + "ContentPresenter")
+            .Single(n => (string?)n.Attribute(Xaml + "Name") == "CommandDockContentHost");
+        Assert.Equal("Collapsed", (string?)host.Attribute("Visibility"));
+        Assert.Equal("Content", (string?)host.Attribute("ContentSource"));
+    }
+
+    [Fact]
+    public void OnlyCommandDockGetsNewTemplate_NoPowerCardOrNewCommandHandler()
+    {
+        var xaml = XDocument.Parse(Source("MainWindow.xaml"));
+        var expander = xaml.Descendants(Presentation + "Expander")
+            .Single(node => (string?)node.Attribute(Xaml + "Name") == "CommandPanelExpander");
+
+        Assert.Equal("{StaticResource CommandDockTransparentHeaderExpander}", (string?)expander.Attribute("Style"));
+        Assert.Equal("CommandPanel_Expanded", (string?)expander.Attribute("Expanded"));
+        Assert.Equal("CommandPanel_Collapsed", (string?)expander.Attribute("Collapsed"));
+        Assert.Equal("False", (string?)expander.Attribute("IsExpanded"));
+        var header = expander.Element(Presentation + "Expander.Header");
+        Assert.NotNull(header);
+        Assert.Empty(header!.Descendants(Presentation + "Border"));
+        Assert.Empty(header.Descendants(Presentation + "Button"));
+        var power = header.Descendants(Presentation + "Path").Single();
+        Assert.Equal("{StaticResource OperatorCommandDockPowerIcon}", (string?)power.Attribute("Data"));
+        Assert.Equal("White", (string?)power.Attribute("Fill"));
+        Assert.Contains(header.Descendants(Presentation + "TextBlock"),
+            text => (string?)text.Attribute("Text") == "IED Command Panel");
+        Assert.NotNull(expander.Descendants(Presentation + "DataGrid").FirstOrDefault());
+
+        Assert.All(xaml.Descendants(Presentation + "Expander")
+            .Where(node => (string?)node.Attribute(Xaml + "Name") != "CommandPanelExpander"),
+            other => Assert.NotEqual("{StaticResource CommandDockTransparentHeaderExpander}",
+                (string?)other.Attribute("Style")));
+    }
+}