diff --git a/src/Nullean.Argh.Generator/CliParserGenerator.Analysis.cs b/src/Nullean.Argh.Generator/CliParserGenerator.Analysis.cs
index 225d1fe..d4cef2f 100644
--- a/src/Nullean.Argh.Generator/CliParserGenerator.Analysis.cs
+++ b/src/Nullean.Argh.Generator/CliParserGenerator.Analysis.cs
@@ -280,6 +280,9 @@ private static bool IsInvocationInsideMapNamespaceConfigure(InvocationExpression
 			entryTypeSnapshot = BuildRegistryNodeSnapshot(entryNode);
 		}
 
+		var (_nsHideHelp, _nsHideSchema) = namespaceEntryType is not null
+			? GetHiddenFlags(namespaceEntryType)
+			: (false, false);
 		return new AIMapNamespace(
 			filePath,
 			spanStart,
@@ -294,7 +297,9 @@ private static bool IsInvocationInsideMapNamespaceConfigure(InvocationExpression
 			HasEntryType: namespaceEntryType is not null,
 			SourceSpanInfo.From(invocation.GetLocation()),
 			ImmutableArray<PendingDiagnostic>.Empty,
-			entryTypeSnapshot);
+			entryTypeSnapshot,
+			NsIsHiddenFromHelp: _nsHideHelp,
+			NsIsHiddenFromSchema: _nsHideSchema);
 	}
 
 	/// <summary>Recursively expands type registration using DiagnosticAccumulator (for Select-step analysis).</summary>
@@ -318,12 +323,15 @@ private static void ExpandTypeRegistrationAcc(
 			var wrapper = new RegistryNode();
 			var outerPrefix = AppendSegment(routePrefix, seg);
 			ExpandTypeRegistrationAcc(acc, location, type, outerPrefix, mergeOuterTypeSegment: true, wrapper, parseOpts, compilation);
+			var (_typeHideHelp, _typeHideSchema) = GetHiddenFlags(type);
 			attachTo.Children.Add(new RegistryNode.NamedCommandNamespaceChild
 			{
 				Segment = seg,
 				Node = wrapper,
 				SummaryOneLiner = GetTypeListingSummaryOneLiner(type),
-				Location = location
+				Location = location,
+				IsHidden = _typeHideHelp,
+				IsHiddenInSchema = _typeHideSchema
 			});
 		}
 	}
@@ -333,7 +341,7 @@ private static RegistryNodeSnapshot BuildRegistryNodeSnapshot(RegistryNode node)
 	{
 		var children = ImmutableArray.CreateBuilder<ChildNamespaceSnapshot>(node.Children.Count);
 		foreach (var ch in node.Children)
-			children.Add(new ChildNamespaceSnapshot(ch.Segment, BuildRegistryNodeSnapshot(ch.Node), ch.SummaryOneLiner));
+			children.Add(new ChildNamespaceSnapshot(ch.Segment, BuildRegistryNodeSnapshot(ch.Node), ch.SummaryOneLiner, ch.IsHidden, ch.IsHiddenInSchema));
 		return new RegistryNodeSnapshot(
 			node.RootCommand,
 			node.Commands.ToImmutableArray(),
@@ -655,7 +663,9 @@ private static void ProcessAnalyzedMapNamespace(
 			Segment = ns.SegmentName,
 			Node = childNode,
 			SummaryOneLiner = ns.NsSummary,
-			Location = ns.DiagnosticSpanInfo.ToLocation()
+			Location = ns.DiagnosticSpanInfo.ToLocation(),
+			IsHidden = ns.NsIsHiddenFromHelp,
+			IsHiddenInSchema = ns.NsIsHiddenFromSchema
 		});
 	}
 
@@ -717,7 +727,9 @@ private static void ApplyRegistryNodeSnapshot(RegistryNodeSnapshot snap, Registr
 				Segment = childSnap.Segment,
 				Node = childNode,
 				SummaryOneLiner = childSnap.SummaryOneLiner,
-				Location = Location.None
+				Location = Location.None,
+				IsHidden = childSnap.IsHidden,
+				IsHiddenInSchema = childSnap.IsHiddenInSchema
 			});
 		}
 		target.SummaryInnerXml = snap.SummaryInnerXml;
diff --git a/src/Nullean.Argh.Generator/CliParserGenerator.CommandModel.cs b/src/Nullean.Argh.Generator/CliParserGenerator.CommandModel.cs
index 777b4a6..817a6d5 100644
--- a/src/Nullean.Argh.Generator/CliParserGenerator.CommandModel.cs
+++ b/src/Nullean.Argh.Generator/CliParserGenerator.CommandModel.cs
@@ -47,6 +47,7 @@ private sealed record CommandModel(
 		bool IsIntrinsic = false,
 		ImmutableArray<string> CommandAliases = default,
 		bool IsHidden = false,
+		bool IsHiddenInSchema = false,
 		bool IsDeprecated = false,
 		string? DeprecationMessage = null,
 		CommandIntentData? Intent = null,
@@ -121,7 +122,8 @@ public static CommandModel FromMethod(
 			var hasParamlessCtor = method.ContainingType is INamedTypeSymbol namedCt && HasPublicParameterlessCtor(namedCt);
 			var (retFq, retIsAsync, retIsVoid, handlerNoInj, handlerParams, handlerLoc, ctorParams, mwData, docId) = ExtractHandlerAnalysis(method);
 			var (isDeprecated, deprecationMsg) = TryGetObsoleteAttribute(method);
-			return new CommandModel(routePrefix, commandName, runName, containingFq, method.Name, !method.IsStatic, hasParamlessCtor, retFq, retIsAsync, retIsVoid, withDocs, handlerNoInj, handlerParams, handlerLoc, ctorParams, docId, docs.SummaryOneLiner, docs.RemarksRendered, docs.SummaryInnerXml, docs.RemarksInnerXml, docs.ExamplesRendered, usage, mwData, IsIntrinsic: HasCommandIntrinsicAttribute(method), CommandAliases: TryGetCommandAliasesFromAttribute(method), IsHidden: HasHiddenAttribute(method), IsDeprecated: isDeprecated, DeprecationMessage: deprecationMsg, Intent: TryGetCommandIntentData(method), Output: BuildCommandOutputFromParameters(withDocs));
+			var (_cmdHideHelp, _cmdHideSchema) = GetHiddenFlags(method);
+			return new CommandModel(routePrefix, commandName, runName, containingFq, method.Name, !method.IsStatic, hasParamlessCtor, retFq, retIsAsync, retIsVoid, withDocs, handlerNoInj, handlerParams, handlerLoc, ctorParams, docId, docs.SummaryOneLiner, docs.RemarksRendered, docs.SummaryInnerXml, docs.RemarksInnerXml, docs.ExamplesRendered, usage, mwData, IsIntrinsic: HasCommandIntrinsicAttribute(method), CommandAliases: TryGetCommandAliasesFromAttribute(method), IsHidden: _cmdHideHelp, IsHiddenInSchema: _cmdHideSchema, IsDeprecated: isDeprecated, DeprecationMessage: deprecationMsg, Intent: TryGetCommandIntentData(method), Output: BuildCommandOutputFromParameters(withDocs));
 		}
 
 		private static ImmutableArray<ParameterModel> BuildParameterModels(
diff --git a/src/Nullean.Argh.Generator/CliParserGenerator.Emit.Dispatch.cs b/src/Nullean.Argh.Generator/CliParserGenerator.Emit.Dispatch.cs
index 20c1048..8b12505 100644
--- a/src/Nullean.Argh.Generator/CliParserGenerator.Emit.Dispatch.cs
+++ b/src/Nullean.Argh.Generator/CliParserGenerator.Emit.Dispatch.cs
@@ -647,7 +647,8 @@ private static void EmitPrintRootHelpHierarchical(StringBuilder sb, AppEmitModel
 		var maxOptWidthRoot = Math.Min(widthCandidatesGlobalRoot.Max(), 40);
 		maxOptWidthRoot = Math.Max(maxOptWidthRoot, "-h, --help".Length);
 
-		var maxNsListingW = app.Root.Children.Count == 0 ? 0 : app.Root.Children.Max(ch => ch.Segment.Length);
+		var visibleRootChildren = app.Root.Children.Where(static ch => !ch.IsHidden).ToList();
+		var maxNsListingW = visibleRootChildren.Count == 0 ? 0 : visibleRootChildren.Max(ch => ch.Segment.Length);
 		var visibleRootCmds = app.Root.Commands.Where(static c => !c.IsHidden).ToList();
 		var maxCmdListingW = visibleRootCmds.Count == 0 ? 0 : visibleRootCmds.Max(c => c.CommandName.Length);
 
@@ -675,10 +676,10 @@ private static void EmitPrintRootHelpHierarchical(StringBuilder sb, AppEmitModel
 			$"\t\t\tConsole.Out.WriteLine(\"  \" + CliHelpFormatting.Placeholder(\"{Escape("--version".PadRight(maxOptWidthRoot))}\") + \"  Show version.\");");
 		EmitHelpOptionRows(sb, rootGlobalFlags, maxOptWidthRoot);
 		sb.AppendLine("\t\t\tConsole.Out.WriteLine();");
-		if (app.Root.Children.Count > 0)
+		if (visibleRootChildren.Count > 0)
 		{
 			sb.AppendLine("\t\t\tConsole.Out.WriteLine(CliHelpFormatting.Section(\"Namespaces:\"));");
-			foreach (var ch in app.Root.Children.OrderBy(ch => ch.Segment, StringComparer.OrdinalIgnoreCase).ThenBy(ch => ch.Segment, StringComparer.Ordinal))
+			foreach (var ch in visibleRootChildren.OrderBy(ch => ch.Segment, StringComparer.OrdinalIgnoreCase).ThenBy(ch => ch.Segment, StringComparer.Ordinal))
 			{
 				var sumArg = string.IsNullOrWhiteSpace(ch.SummaryOneLiner)
 					? "null"
@@ -740,9 +741,8 @@ private static void EmitCommandNamespaceHelpPrinter(StringBuilder sb, ImmutableA
 		var maxOptWidth = Math.Min(widthCandidatesNs.Max(), 40);
 		maxOptWidth = Math.Max(maxOptWidth, "-h, --help".Length);
 
-		var maxChildNsListingW = 0;
-		if (node.Children.Count > 0)
-			maxChildNsListingW = node.Children.Max(ch => FormatQualifiedCliPath(path, ch.Segment).Length);
+		var visibleChildNamespaces = node.Children.Where(static ch => !ch.IsHidden).ToList();
+		var maxChildNsListingW = visibleChildNamespaces.Count == 0 ? 0 : visibleChildNamespaces.Max(ch => FormatQualifiedCliPath(path, ch.Segment).Length);
 		var maxChildCmdListingW = 0;
 		var visibleNodeCmds = node.Commands.Where(static c => !c.IsHidden).ToList();
 		if (visibleNodeCmds.Count > 0)
@@ -781,10 +781,10 @@ private static void EmitCommandNamespaceHelpPrinter(StringBuilder sb, ImmutableA
 			}
 		}
 
-		if (node.Children.Count > 0)
+		if (visibleChildNamespaces.Count > 0)
 		{
 			sb.AppendLine("\t\t\tConsole.Out.WriteLine(CliHelpFormatting.Section(\"Namespaces:\"));");
-			foreach (var ch in node.Children.OrderBy(ch => ch.Segment, StringComparer.OrdinalIgnoreCase).ThenBy(ch => ch.Segment, StringComparer.Ordinal))
+			foreach (var ch in visibleChildNamespaces.OrderBy(ch => ch.Segment, StringComparer.OrdinalIgnoreCase).ThenBy(ch => ch.Segment, StringComparer.Ordinal))
 			{
 				var fullNs = FormatQualifiedCliPath(path, ch.Segment);
 				var sumArg = string.IsNullOrWhiteSpace(ch.SummaryOneLiner)
diff --git a/src/Nullean.Argh.Generator/CliParserGenerator.Models.cs b/src/Nullean.Argh.Generator/CliParserGenerator.Models.cs
index cd2dfdb..9b5a717 100644
--- a/src/Nullean.Argh.Generator/CliParserGenerator.Models.cs
+++ b/src/Nullean.Argh.Generator/CliParserGenerator.Models.cs
@@ -37,6 +37,8 @@ public sealed class NamedCommandNamespaceChild
 			/// <summary>First non-empty XML summary from the first generic <c>Add</c> handler type in this namespace block.</summary>
 			public string SummaryOneLiner = "";
 			public Location Location = Location.None;
+			public bool IsHidden = false;
+			public bool IsHiddenInSchema = false;
 		}
 	}
 
@@ -254,7 +256,9 @@ private sealed record AIMapNamespace(
 		/// Contains root commands, regular commands, and nested children from ExpandTypeRegistration.
 		/// Null when there is no entry type.
 		/// </summary>
-		RegistryNodeSnapshot? EntryTypeSnapshot)
+		RegistryNodeSnapshot? EntryTypeSnapshot,
+		bool NsIsHiddenFromHelp = false,
+		bool NsIsHiddenFromSchema = false)
 		: AnalyzedInvocation(FilePath, SpanStart);
 
 	/// <summary>Symbol-free snapshot of a RegistryNode subtree produced during analysis.</summary>
@@ -271,7 +275,9 @@ private sealed record RegistryNodeSnapshot(
 	private sealed record ChildNamespaceSnapshot(
 		string Segment,
 		RegistryNodeSnapshot Node,
-		string SummaryOneLiner);
+		string SummaryOneLiner,
+		bool IsHidden = false,
+		bool IsHiddenInSchema = false);
 
 	// ─────────────────────────────────────────────────────────────────────────────
 
diff --git a/src/Nullean.Argh.Generator/CliParserGenerator.ParameterModel.cs b/src/Nullean.Argh.Generator/CliParserGenerator.ParameterModel.cs
index c830183..93a15b8 100644
--- a/src/Nullean.Argh.Generator/CliParserGenerator.ParameterModel.cs
+++ b/src/Nullean.Argh.Generator/CliParserGenerator.ParameterModel.cs
@@ -59,6 +59,7 @@ private sealed record ParameterModel(
 		bool ExpandUserProfileBeforeBind = false,
 		ImmutableArray<ValidationConstraint> Validations = default,
 		bool IsHidden = false,
+		bool IsHiddenInSchema = false,
 		bool IsVariadic = false,
 		/// <summary>
 		/// True when the property is from a cross-assembly type (DeclaringSyntaxReferences empty) and has no
@@ -151,6 +152,7 @@ private static ParameterModel BuildCollectionParameterModel(
 			if (isVariadic) required = false;
 			var (isOutputColl, outputFormatsColl) = TryGetCommandOutputAttribute(attributeHost);
 			var (isDeprecatedColl, deprecationMsgColl) = TryGetObsoleteAttribute(attributeHost);
+			var (_colHideHelp, _colHideSchema) = GetHiddenFlags(attributeHost);
 			return new ParameterModel(
 				symbolName,
 				localVarName,
@@ -190,7 +192,8 @@ private static ParameterModel BuildCollectionParameterModel(
 				AsParametersClrName: asParams?.ClrName,
 				ExpandUserProfileBeforeBind: expandProfileElem,
 				Validations: collValidations,
-				IsHidden: HasHiddenAttribute(attributeHost),
+				IsHidden: _colHideHelp,
+				IsHiddenInSchema: _colHideSchema,
 				IsVariadic: isVariadic,
 				IsConfirmationSkip: HasConfirmationSkipAttribute(attributeHost),
 				IsDryRun: HasDryRunAttribute(attributeHost),
@@ -252,6 +255,7 @@ public static ParameterModel From(IParameterSymbol p, DiagnosticAccumulator? rep
 			var expandProf = TryReadExpandUserProfileBeforeBind(p, sk);
 			var (isOutputP, outputFormatsP) = TryGetCommandOutputAttribute(p);
 			var (isDeprecatedP, deprecationMsgP) = TryGetObsoleteAttribute(p);
+			var (_paramHideHelp, _paramHideSchema) = GetHiddenFlags(p);
 			return new ParameterModel(
 				p.Name,
 				SafeLocalName(p.Name),
@@ -273,7 +277,8 @@ public static ParameterModel From(IParameterSymbol p, DiagnosticAccumulator? rep
 				EnumMemberDocs: enumDocs,
 				ExpandUserProfileBeforeBind: expandProf,
 				Validations: validations,
-				IsHidden: HasHiddenAttribute(p),
+				IsHidden: _paramHideHelp,
+				IsHiddenInSchema: _paramHideSchema,
 				IsConfirmationSkip: HasConfirmationSkipAttribute(p),
 				IsDryRun: HasDryRunAttribute(p),
 				IsCommandOutput: isOutputP,
@@ -310,6 +315,7 @@ public static ParameterModel FromOptionsProperty(IPropertySymbol prop, Compilati
 			var validations = ReadValidationConstraints(prop, sk, typeName);
 			var defLit = QualifyOptionsEnumDefaultLiteral(defaultValueLiteral, sk, enumFq, enumMembers);
 			var expandProf = TryReadExpandUserProfileBeforeBind(prop, sk);
+			var (_propHideHelp, _propHideSchema) = GetHiddenFlags(prop);
 			return new ParameterModel(
 				prop.Name,
 				SafeLocalName(prop.Name),
@@ -331,7 +337,8 @@ public static ParameterModel FromOptionsProperty(IPropertySymbol prop, Compilati
 				EnumMemberDocs: enumDocs,
 				ExpandUserProfileBeforeBind: expandProf,
 				Validations: validations,
-				IsHidden: HasHiddenAttribute(prop),
+				IsHidden: _propHideHelp,
+				IsHiddenInSchema: _propHideSchema,
 				UsesRuntimeDefault: isCrossAssemblyDefault,
 				IsNullableAnnotated: prop.Type.NullableAnnotation == NullableAnnotation.Annotated
 					|| prop.Type is INamedTypeSymbol { OriginalDefinition.SpecialType: SpecialType.System_Nullable_T },
@@ -367,6 +374,7 @@ public static ParameterModel FromOptionsField(IFieldSymbol field, Compilation? c
 			var validations = ReadValidationConstraints(field, sk, typeName);
 			var defLit = QualifyOptionsEnumDefaultLiteral(defaultValueLiteral, sk, enumFq, enumMembers);
 			var expandProf = TryReadExpandUserProfileBeforeBind(field, sk);
+			var (_fieldHideHelp, _fieldHideSchema) = GetHiddenFlags(field);
 			return new ParameterModel(
 				field.Name,
 				SafeLocalName(field.Name),
@@ -387,7 +395,8 @@ public static ParameterModel FromOptionsField(IFieldSymbol field, Compilation? c
 				EnumMemberCliNames: enumCliNames,
 				ExpandUserProfileBeforeBind: expandProf,
 				Validations: validations,
-				IsHidden: HasHiddenAttribute(field),
+				IsHidden: _fieldHideHelp,
+				IsHiddenInSchema: _fieldHideSchema,
 				UsesRuntimeDefault: isCrossAssemblyDefault,
 				IsNullableAnnotated: field.Type.NullableAnnotation == NullableAnnotation.Annotated
 					|| field.Type is INamedTypeSymbol { OriginalDefinition.SpecialType: SpecialType.System_Nullable_T });
diff --git a/src/Nullean.Argh.Generator/CliParserGenerator.Schema.cs b/src/Nullean.Argh.Generator/CliParserGenerator.Schema.cs
index 17a6222..8c602bb 100644
--- a/src/Nullean.Argh.Generator/CliParserGenerator.Schema.cs
+++ b/src/Nullean.Argh.Generator/CliParserGenerator.Schema.cs
@@ -163,7 +163,7 @@ private static void EmitCliCommandSchemaBody(StringBuilder sb, CommandModel cmd,
 			var aliasArr = string.Join(", ", cmd.CommandAliases.Select(a => $"\"{Escape(a)}\""));
 			sb.Append($"{indent}\tAliases: new string[] {{ {aliasArr} }}");
 		}
-		if (cmd.IsHidden)
+		if (cmd.IsHiddenInSchema)
 		{
 			sb.AppendLine(",");
 			sb.Append($"{indent}\tHidden: true");
@@ -461,7 +461,7 @@ private static string EmitCliParameterSchemaNewExpression(ParameterModel p)
 			sb.Append($", ElementType: \"{elemType}\"");
 		}
 
-		if (p.IsHidden)
+		if (p.IsHiddenInSchema)
 			sb.Append(", Hidden: true");
 
 		if (p.IsVariadic)
diff --git a/src/Nullean.Argh.Generator/CliParserGenerator.SymbolReaders.cs b/src/Nullean.Argh.Generator/CliParserGenerator.SymbolReaders.cs
index 748010e..d759713 100644
--- a/src/Nullean.Argh.Generator/CliParserGenerator.SymbolReaders.cs
+++ b/src/Nullean.Argh.Generator/CliParserGenerator.SymbolReaders.cs
@@ -40,16 +40,24 @@ private static bool HasCommandIntrinsicAttribute(IMethodSymbol method)
 		return false;
 	}
 
-	private static bool HasHiddenAttribute(ISymbol symbol)
+	private static (bool HideHelp, bool HideSchema) GetHiddenFlags(ISymbol symbol)
 	{
 		foreach (var ad in symbol.GetAttributes())
 		{
 			if (ad.AttributeClass?.Name == "HiddenAttribute" &&
 			    ad.AttributeClass.ContainingNamespace?.ToDisplayString() == "Nullean.Argh")
-				return true;
+			{
+				bool help = true, schema = false;
+				foreach (var na in ad.NamedArguments)
+				{
+					if (na.Key == "Help" && na.Value.Value is bool h) help = h;
+					if (na.Key == "Schema" && na.Value.Value is bool s) schema = s;
+				}
+				return (help, schema);
+			}
 		}
 
-		return false;
+		return (false, false);
 	}
 
 	private static string? TryGetCommandNameAttribute(IMethodSymbol method)
diff --git a/src/Nullean.Argh.Interfaces/Annotations/Attributes.cs b/src/Nullean.Argh.Interfaces/Annotations/Attributes.cs
index 54db4a5..3343dbb 100644
--- a/src/Nullean.Argh.Interfaces/Annotations/Attributes.cs
+++ b/src/Nullean.Argh.Interfaces/Annotations/Attributes.cs
@@ -183,10 +183,18 @@ public sealed class EnumValueAttribute : Attribute
 }
 
 /// <summary>
-/// Marks a command method or parameter as hidden from user-facing help and autocomplete suggestions.
-/// The command or parameter still parses and works correctly, and appears in <c>__schema</c> output
-/// with <c>hidden: true</c> so tooling can suppress it selectively.
+/// Marks a command method, parameter, or namespace class as hidden from user-facing help and autocomplete.
+/// By default (<c>Help=true, Schema=false</c>) the item is suppressed from help output but remains fully
+/// visible in <c>__schema</c> output without any hidden marker. Set <c>Schema=true</c> to also mark it
+/// with <c>hidden: true</c> in the schema so tooling can suppress it selectively.
+/// The command or parameter still parses and works correctly regardless of these flags.
 /// </summary>
-[AttributeUsage(AttributeTargets.Method | AttributeTargets.Parameter | AttributeTargets.Property)]
-public sealed class HiddenAttribute : Attribute;
+[AttributeUsage(AttributeTargets.Method | AttributeTargets.Parameter | AttributeTargets.Property | AttributeTargets.Class)]
+public sealed class HiddenAttribute : Attribute
+{
+    /// <summary>When <c>true</c> (default), the item is suppressed from user-facing help listings.</summary>
+    public bool Help { get; set; } = true;
+    /// <summary>When <c>true</c>, the item is marked <c>hidden: true</c> in <c>__schema</c> output. Default is <c>false</c>.</summary>
+    public bool Schema { get; set; } = false;
+}
 
diff --git a/tests/Nullean.Argh.IntegrationTests/Completions/SchemaTests.cs b/tests/Nullean.Argh.IntegrationTests/Completions/SchemaTests.cs
index 1933dd7..99f33cd 100644
--- a/tests/Nullean.Argh.IntegrationTests/Completions/SchemaTests.cs
+++ b/tests/Nullean.Argh.IntegrationTests/Completions/SchemaTests.cs
@@ -168,6 +168,21 @@ public void Schema_hidden_parameter_has_hidden_true()
 		nameParam.TryGetProperty("hidden", out _).Should().BeFalse();
 	}
 
+	[Fact]
+	public void Schema_hidden_namespace_appears_in_schema_without_hidden_flag()
+	{
+		var result = CliHostRunner.Run("__schema");
+		result.ExitCode.Should().Be(0);
+		using var doc = JsonDocument.Parse(CliHostRunner.StdoutText(result));
+		var namespaces = doc.RootElement.GetProperty("namespaces");
+
+		// [Hidden] default: Help=true, Schema=false — namespace appears in schema, no hidden:true marker
+		var hiddenNs = namespaces.EnumerateArray()
+			.FirstOrDefault(n => n.GetProperty("segment").GetString() == "schema-hidden-ns");
+		hiddenNs.ValueKind.Should().Be(JsonValueKind.Object);
+		hiddenNs.TryGetProperty("hidden", out _).Should().BeFalse();
+	}
+
 	[Fact]
 	public void Schema_default_value_is_emitted_for_parameters_with_defaults()
 	{
diff --git a/tests/Nullean.Argh.IntegrationTests/Help/RootAndNamespaceHelpTests.cs b/tests/Nullean.Argh.IntegrationTests/Help/RootAndNamespaceHelpTests.cs
index 71244ec..b09c598 100644
--- a/tests/Nullean.Argh.IntegrationTests/Help/RootAndNamespaceHelpTests.cs
+++ b/tests/Nullean.Argh.IntegrationTests/Help/RootAndNamespaceHelpTests.cs
@@ -222,4 +222,24 @@ storage list
 		TrimLines(text).Should().Be(TrimLines(expected));
 		text.Should().NotContain("hello");
 	}
+
+	[Fact]
+	public void RootHelp_does_not_list_hidden_namespaces()
+	{
+		var result = CliHostRunner.Run(
+			new Dictionary<string, string>(StringComparer.Ordinal) { ["NO_COLOR"] = "1" },
+			"--help");
+		result.ExitCode.Should().Be(0);
+		var text = ConsoleOutput.Normalize(CliHostRunner.StdoutText(result));
+		text.Should().NotContain("schema-hidden-ns");
+		text.Should().NotContain("schema-hidden-schema-ns");
+	}
+
+	[Fact]
+	public void Hidden_namespace_is_still_callable()
+	{
+		var result = CliHostRunner.Run("schema-hidden-ns", "internal-cmd");
+		result.ExitCode.Should().Be(0);
+		CliHostRunner.StdoutText(result).Should().Contain("internal");
+	}
 }
diff --git a/tests/Nullean.Argh.Tests/CliRegistrationModule.cs b/tests/Nullean.Argh.Tests/CliRegistrationModule.cs
index 136aa9d..354c719 100644
--- a/tests/Nullean.Argh.Tests/CliRegistrationModule.cs
+++ b/tests/Nullean.Argh.Tests/CliRegistrationModule.cs
@@ -93,6 +93,8 @@ internal static void RegisterCommands()
 		app.Map("schema-intent-destructive", SchemaIntentHandlers.SchemaIntentDestructive);
 		app.Map("schema-intent-read", SchemaIntentHandlers.SchemaIntentRead);
 		app.Map("schema-output-formats", SchemaOutputHandlers.SchemaOutputFormats);
+		app.MapNamespace<SchemaHiddenNamespace>("schema-hidden-ns");
+		app.MapNamespace<SchemaHiddenSchemaNamespace>("schema-hidden-schema-ns");
 		app.MapNamespace<StorageCliCommands>("storage", g =>
 		{
 			g.UseNamespaceOptions<TestStorageCommandNamespaceOptions>();
diff --git a/tests/Nullean.Argh.Tests/Fixtures/SchemaSpecificHandlers.cs b/tests/Nullean.Argh.Tests/Fixtures/SchemaSpecificHandlers.cs
index 439007f..8f7f4b3 100644
--- a/tests/Nullean.Argh.Tests/Fixtures/SchemaSpecificHandlers.cs
+++ b/tests/Nullean.Argh.Tests/Fixtures/SchemaSpecificHandlers.cs
@@ -22,7 +22,7 @@ public static void SchemaSeparatorList(
 	/// <param name="name">Visible name flag.</param>
 	/// <param name="internalId">Internal ID (hidden).</param>
 	[NoOptionsInjection]
-	public static void SchemaHiddenParam(string name, [Hidden] string? internalId = null) =>
+	public static void SchemaHiddenParam(string name, [Hidden(Schema = true)] string? internalId = null) =>
 		Console.Out.WriteLine($"name:{name}");
 }
 
@@ -34,7 +34,7 @@ internal sealed class SchemaHiddenCommands
 	public static void VisibleCmd() => Console.Out.WriteLine("visible");
 
 	/// <summary>A command that is hidden from help and autocomplete.</summary>
-	[Hidden]
+	[Hidden(Schema = true)]
 	[NoOptionsInjection]
 	public static void HiddenCmd() => Console.Out.WriteLine("hidden");
 }
@@ -93,6 +93,24 @@ public static void SchemaIntentRead(
 		Console.Out.WriteLine("list");
 }
 
+/// <summary>Schema test: a namespace hidden from help only (default [Hidden]).</summary>
+[Hidden]
+internal sealed class SchemaHiddenNamespace
+{
+	/// <summary>An internal command inside the hidden namespace.</summary>
+	[NoOptionsInjection]
+	public static void InternalCmd() => Console.Out.WriteLine("internal");
+}
+
+/// <summary>Schema test: a namespace hidden from both help and schema.</summary>
+[Hidden(Schema = true)]
+internal sealed class SchemaHiddenSchemaNamespace
+{
+	/// <summary>An internal command inside the hidden-from-schema namespace.</summary>
+	[NoOptionsInjection]
+	public static void InternalCmd() => Console.Out.WriteLine("internal-schema");
+}
+
 /// <summary>Enum for output format selection.</summary>
 internal enum OutputFormat { Json, Table, Csv }