diff --git a/MainWindow.xaml b/MainWindow.xaml
index c14ff0b23..a6faf4f24 100644
--- a/MainWindow.xaml
+++ b/MainWindow.xaml
@@ -377,6 +377,19 @@
                                                             <ContextMenu/>
                                                         </TextBlock.ContextMenu>
                                                     </TextBlock>
+                                                    <!-- Permanent 6px lane: Read progress changes opacity, never card geometry. -->
+                                                    <Grid Height="6" Margin="8,5,8,0" ClipToBounds="True"
+                                                          ToolTip="{Binding BusyStage}">
+                                                        <Border Height="3" VerticalAlignment="Center"
+                                                                CornerRadius="2" Background="#DCE6F2"/>
+                                                        <ProgressBar x:Name="IedCardBrowserReadProgress"
+                                                                     Height="3" VerticalAlignment="Center"
+                                                                     Minimum="0" Maximum="100"
+                                                                     Value="{Binding DiscoveryProgressPercent, Mode=OneWay}"
+                                                                     Style="{StaticResource DiscoveryProgressBar}"
+                                                                     Opacity="0"
+                                                                     IsHitTestVisible="False"/>
+                                                    </Grid>
                                                 </StackPanel>
                                       <!-- Adaptive five-slot action bar. It spans the card and reserves the relay-icon area so Play/Stop never clip. -->
                                       <Grid Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2" Margin="62,4,1,0" Panel.ZIndex="10">
@@ -481,7 +494,9 @@
                                                 <Setter TargetName="BusyOverlay" Property="Visibility" Value="Visible"/>
                                             </DataTrigger>
                                             <DataTrigger Binding="{Binding IsBrowserReading}" Value="True">
-                                                <Setter TargetName="BusyOverlay" Property="Visibility" Value="Visible"/>
+                                                <!-- Browser MMS Read leaves live card/actions visible; only
+                                                     the fixed-height progress lane illuminates. -->
+                                                <Setter TargetName="IedCardBrowserReadProgress" Property="Opacity" Value="1"/>
                                             </DataTrigger>
                                         </DataTemplate.Triggers>
                                     </DataTemplate>
diff --git a/Models/IedBrowserReadPlan.cs b/Models/IedBrowserReadPlan.cs
index 0ce1bf267..ed50f2eb1 100644
--- a/Models/IedBrowserReadPlan.cs
+++ b/Models/IedBrowserReadPlan.cs
@@ -28,8 +28,10 @@ public static IedBrowserReadSelectionKind SelectionKind(IedBrowserTreeRow? page)
             _ => IedBrowserReadSelectionKind.FcAttributes
         };
 
+    // Explicit, schema-verified MMS Read includes substitution (SV), originator
+    // (OR) and blocking (BL) attributes. These are observations, never writes.
     private static readonly HashSet<string> ReadableFc = new(
-        ["ST", "MX", "CF", "DC", "SP", "SG", "SE", "EX"], StringComparer.OrdinalIgnoreCase);
+        ["ST", "MX", "CF", "DC", "SP", "SG", "SE", "EX", "SV", "OR", "BL"], StringComparer.OrdinalIgnoreCase);
 
     /// <summary>
     /// FC CO denotes command parameters, not scalar MMS Read targets.
diff --git a/tests/ARSAS.Tests/P0FBrowserReadCoverageAndCardTests.cs b/tests/ARSAS.Tests/P0FBrowserReadCoverageAndCardTests.cs
new file mode 100644
index 000000000..760597384
--- /dev/null
+++ b/tests/ARSAS.Tests/P0FBrowserReadCoverageAndCardTests.cs
@@ -0,0 +1,67 @@
+using System.Xml.Linq;
+using AR.Iec61850.Discovery;
+using ArIED61850Tester.Models;
+
+namespace ARSAS.Tests;
+
+public sealed class P0FBrowserReadCoverageAndCardTests
+{
+    [Fact]
+    public void ExplicitReadLnIncludesVerifiedSubstitutionOriginAndBlockingWithoutControlOperations()
+    {
+        var attributes = new[] { ("subEna", "SV"), ("subVal", "SV"), ("subQ", "SV"),
+            ("subID", "SV"), ("opRcvd", "OR"), ("opOk", "OR"),
+            ("blkEna", "BL"), ("stVal", "ST"), ("ctlVal", "CO") };
+        var dataObject = new LiveIedDataObjectModel
+        {
+            Name = "Pos", Reference = "LD/XCBR1.Pos",
+            Attributes = attributes.Select(a => new LiveIedDataAttributeModel
+            {
+                ObjectReference = "LD/XCBR1.Pos",
+                AttributePath = "Pos." + a.Item1,
+                MmsReference = "LD/XCBR1$" + a.Item2 + "$Pos$" + a.Item1,
+                FunctionalConstraint = a.Item2,
+                MmsType = "Boolean",
+                TypeSource = "LiveTypeSpecification"
+            }).ToArray()
+        };
+        var ln = new LiveIedLogicalNodeModel { DataObjects = [dataObject] };
+        var model = new LiveIedModelDiscoveryDocument
+        {
+            LogicalDevices = [new LiveIedLogicalDeviceModel
+            {
+                LogicalNodes = [ln]
+            }]
+        };
+        var page = new IedBrowserTreeRow("model/ln/XCBR1", "XCBR1", "LN", 1, ln);
+        var plan = IedBrowserReadPlan.Build(model, page, readAll: false);
+        Assert.Equal(8, plan.Count);
+        Assert.All(new[] { "SV", "OR", "BL" },
+            fc => Assert.Contains(plan, target => target.FunctionalConstraint == fc));
+        Assert.DoesNotContain(plan, target => target.FunctionalConstraint == "CO");
+        Assert.Contains(plan, target => target.Reference.EndsWith("$subEna", StringComparison.Ordinal));
+        Assert.Contains(plan, target => target.Reference.EndsWith("$blkEna", StringComparison.Ordinal));
+    }
+
+    [Fact]
+    public void BrowserCardReadUsesPermanentLaneAndNeverInvokesBusyOverlay()
+    {
+        var dir = new DirectoryInfo(AppContext.BaseDirectory);
+        string? file = null;
+        while (dir != null)
+        {
+            var candidate = Path.Combine(dir.FullName, "MainWindow.xaml");
+            if (File.Exists(candidate)) { file = candidate; break; }
+            dir = dir.Parent;
+        }
+        Assert.NotNull(file);
+        var xaml = File.ReadAllText(file!);
+        Assert.Contains("Height=\"6\" Margin=\"8,5,8,0\"", xaml);
+        Assert.Contains("x:Name=\"IedCardBrowserReadProgress\"", xaml);
+        Assert.Contains("TargetName=\"IedCardBrowserReadProgress\" Property=\"Opacity\" Value=\"1\"", xaml);
+        Assert.DoesNotContain(
+            "<DataTrigger Binding=\"{Binding IsBrowserReading}\" Value=\"True\">\n                                                <Setter TargetName=\"BusyOverlay\"",
+            xaml);
+        _ = XDocument.Parse(xaml);
+    }
+}