diff --git a/src/System.CommandLine.ApiCompatibility.Tests/ApiCompatibilityApprovalTests.System_CommandLine_api_is_not_changed.approved.txt b/src/System.CommandLine.ApiCompatibility.Tests/ApiCompatibilityApprovalTests.System_CommandLine_api_is_not_changed.approved.txt
index e16bab36bb..6bd02eb28d 100644
--- a/src/System.CommandLine.ApiCompatibility.Tests/ApiCompatibilityApprovalTests.System_CommandLine_api_is_not_changed.approved.txt
+++ b/src/System.CommandLine.ApiCompatibility.Tests/ApiCompatibilityApprovalTests.System_CommandLine_api_is_not_changed.approved.txt
@@ -100,6 +100,7 @@
     public System.Collections.Generic.List<System.Action<System.CommandLine.Parsing.OptionResult>> Validators { get; }
     public System.Type ValueType { get; }
     public System.Collections.Generic.IEnumerable<System.CommandLine.Completions.CompletionItem> GetCompletions(System.CommandLine.Completions.CompletionContext context)
+    public System.Object GetDefaultValue()
   public class Option<T> : Option
     .ctor(System.String name, System.String[] aliases)
     public Func<System.CommandLine.Parsing.ArgumentResult,T> CustomParser { get; set; }
@@ -128,6 +129,7 @@
     public System.CommandLine.Parsing.OptionResult GetResult(Option option)
     public System.CommandLine.Parsing.DirectiveResult GetResult(Directive directive)
     public System.CommandLine.Parsing.SymbolResult GetResult(Symbol symbol)
+    public System.CommandLine.Parsing.SymbolResult GetResult(System.String name)
     public T GetValue<T>(Argument<T> argument)
     public T GetValue<T>(Option<T> option)
     public T GetValue<T>(System.String name)
@@ -178,48 +180,11 @@ System.CommandLine.Completions
 System.CommandLine.Help
   public class HelpAction : System.CommandLine.Invocation.SynchronousCommandLineAction
     .ctor()
-    public HelpBuilder Builder { get; set; }
     public System.Int32 Invoke(System.CommandLine.ParseResult parseResult)
-  public class HelpBuilder
-    .ctor(System.Int32 maxWidth = 2147483647)
-    public System.Int32 MaxWidth { get; }
-    public System.Void CustomizeLayout(System.Func<HelpContext,System.Collections.Generic.IEnumerable<System.Func<HelpContext,System.Boolean>>> getLayout)
-    public System.Void CustomizeSymbol(System.CommandLine.Symbol symbol, System.Func<HelpContext,System.String> firstColumnText = null, System.Func<HelpContext,System.String> secondColumnText = null, System.Func<HelpContext,System.String> defaultValue = null)
-    public System.Void CustomizeSymbol(System.CommandLine.Symbol symbol, System.String firstColumnText = null, System.String secondColumnText = null, System.String defaultValue = null)
-    public TwoColumnHelpRow GetTwoColumnRow(System.CommandLine.Symbol symbol, HelpContext context)
-    public System.Void Write(HelpContext context)
-    public System.Void Write(System.CommandLine.Command command, System.IO.TextWriter writer)
-    public System.Void WriteColumns(System.Collections.Generic.IReadOnlyList<TwoColumnHelpRow> items, HelpContext context)
-   static class Default
-    public static System.Func<HelpContext,System.Boolean> AdditionalArgumentsSection()
-    public static System.Func<HelpContext,System.Boolean> CommandArgumentsSection()
-    public static System.Func<HelpContext,System.Boolean> CommandUsageSection()
-    public static System.String GetArgumentDefaultValue(System.CommandLine.Argument argument)
-    public static System.String GetArgumentDescription(System.CommandLine.Argument argument)
-    public static System.String GetArgumentUsageLabel(System.CommandLine.Argument argument)
-    public static System.String GetCommandUsageLabel(System.CommandLine.Command symbol)
-    public static System.Collections.Generic.IEnumerable<System.Func<HelpContext,System.Boolean>> GetLayout()
-    public static System.String GetOptionUsageLabel(System.CommandLine.Option symbol)
-    public static System.Func<HelpContext,System.Boolean> OptionsSection()
-    public static System.Func<HelpContext,System.Boolean> SubcommandsSection()
-    public static System.Func<HelpContext,System.Boolean> SynopsisSection()
-  public class HelpContext
-    .ctor(HelpBuilder helpBuilder, System.CommandLine.Command command, System.IO.TextWriter output, System.CommandLine.ParseResult parseResult = null)
-    public System.CommandLine.Command Command { get; }
-    public HelpBuilder HelpBuilder { get; }
-    public System.IO.TextWriter Output { get; }
-    public System.CommandLine.ParseResult ParseResult { get; }
   public class HelpOption : System.CommandLine.Option<System.Boolean>
     .ctor()
     .ctor(System.String name, System.String[] aliases)
     public System.CommandLine.Invocation.CommandLineAction Action { get; set; }
-  public class TwoColumnHelpRow, System.IEquatable<TwoColumnHelpRow>
-    .ctor(System.String firstColumnText, System.String secondColumnText)
-    public System.String FirstColumnText { get; }
-    public System.String SecondColumnText { get; }
-    public System.Boolean Equals(System.Object obj)
-    public System.Boolean Equals(TwoColumnHelpRow other)
-    public System.Int32 GetHashCode()
 System.CommandLine.Invocation
   public abstract class AsynchronousCommandLineAction : CommandLineAction
     public System.Threading.Tasks.Task<System.Int32> InvokeAsync(System.CommandLine.ParseResult parseResult, System.Threading.CancellationToken cancellationToken = null)
diff --git a/src/System.CommandLine.Tests/GetValueByNameParserTests.cs b/src/System.CommandLine.Tests/GetValueByNameParserTests.cs
index 9d5c1465b7..7a2a8721e7 100644
--- a/src/System.CommandLine.Tests/GetValueByNameParserTests.cs
+++ b/src/System.CommandLine.Tests/GetValueByNameParserTests.cs
@@ -194,6 +194,48 @@ public void When_an_option_and_argument_use_same_name_on_the_same_level_of_the_t
             .Where(ex => ex.Message == $"Command {command.Name} has more than one child named \"{sameName}\".");
     }
 
+    [Fact]
+    public void When_options_use_same_name_on_different_levels_of_the_tree_no_exception_is_thrown()
+    {
+        const string sameName = "same";
+
+        RootCommand command = new()
+        {
+            new Command("left")
+            {
+                new Option<int>(sameName)
+            },
+            new Command("right")
+            {
+                new Option<int>(sameName)
+            },
+        };
+
+        command.Parse($"left {sameName} 1").GetValue<int>(sameName).Should().Be(1);
+        command.Parse($"right {sameName} 2").GetValue<int>(sameName).Should().Be(2);
+    }
+
+    [Fact]
+    public void When_the_same_option_used_in_different_levels_of_the_tree_no_exception_is_thrown()
+    {
+        Option<int> multipleParents = new("--int");
+
+        RootCommand command = new()
+        {
+            new Command("left")
+            {
+                multipleParents
+            },
+            new Command("right")
+            {
+                multipleParents
+            },
+        };
+
+        command.Parse($"left {multipleParents.Name} 1").GetValue<int>(multipleParents.Name).Should().Be(1);
+        command.Parse($"right {multipleParents.Name} 2").GetValue<int>(multipleParents.Name).Should().Be(2);
+    }
+
     [Fact]
     public void When_an_option_and_argument_use_same_name_on_different_levels_of_the_tree_the_value_which_belongs_to_parsed_command_is_returned()
     {
diff --git a/src/System.CommandLine.Tests/Help/CustomHelpAction.cs b/src/System.CommandLine.Tests/Help/CustomHelpAction.cs
new file mode 100644
index 0000000000..cac66dc599
--- /dev/null
+++ b/src/System.CommandLine.Tests/Help/CustomHelpAction.cs
@@ -0,0 +1,35 @@
+using System.CommandLine.Invocation;
+
+namespace System.CommandLine.Help
+{
+    /// <summary>
+    /// Provides command line help.
+    /// </summary>
+    public sealed class CustomHelpAction : SynchronousCommandLineAction
+    {
+        private HelpBuilder? _builder;
+
+        /// <summary>
+        /// Specifies an <see cref="Builder"/> to be used to format help output when help is requested.
+        /// </summary>
+        internal HelpBuilder Builder
+        {
+            get => _builder ??= new HelpBuilder(Console.IsOutputRedirected ? int.MaxValue : Console.WindowWidth);
+            set => _builder = value ?? throw new ArgumentNullException(nameof(value));
+        }
+
+        /// <inheritdoc />
+        public override int Invoke(ParseResult parseResult)
+        {
+            var output = parseResult.Configuration.Output;
+
+            var helpContext = new HelpContext(Builder,
+                                              parseResult.CommandResult.Command,
+                                              output);
+
+            Builder.Write(helpContext);
+
+            return 0;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/System.CommandLine.Tests/Help/HelpBuilderExtensions.cs b/src/System.CommandLine.Tests/Help/HelpBuilderExtensions.cs
index 202fb93453..6fbc826bd0 100644
--- a/src/System.CommandLine.Tests/Help/HelpBuilderExtensions.cs
+++ b/src/System.CommandLine.Tests/Help/HelpBuilderExtensions.cs
@@ -8,7 +8,7 @@ namespace System.CommandLine.Tests.Help
 {
     public static class HelpBuilderExtensions
     {
-        public static void Write(
+        internal static void Write(
             this HelpBuilder builder,
             Command command,
             TextWriter writer) =>
diff --git a/src/System.CommandLine.Tests/Help/HelpBuilderTests.Customization.cs b/src/System.CommandLine.Tests/Help/HelpBuilderTests.Customization.cs
index 46b084551a..b2d9335ed3 100644
--- a/src/System.CommandLine.Tests/Help/HelpBuilderTests.Customization.cs
+++ b/src/System.CommandLine.Tests/Help/HelpBuilderTests.Customization.cs
@@ -94,7 +94,7 @@ public void Option_can_customize_first_column_text_based_on_parse_result()
                                                 : optionBFirstColumnText);
             command.Options.Add(new HelpOption()
             {
-                Action = new HelpAction()
+                Action = new CustomHelpAction()
                 {
                     Builder = helpBuilder
                 }
@@ -140,7 +140,7 @@ public void Option_can_customize_second_column_text_based_on_parse_result()
                                                 : optionBDescription);
             command.Options.Add(new HelpOption
             {
-                Action = new HelpAction
+                Action = new CustomHelpAction
                 { 
                     Builder = helpBuilder
                 }
@@ -269,7 +269,7 @@ public void Option_can_fallback_to_default_when_customizing(bool conditionA, boo
 
             command.Options.Add(new HelpOption
             {
-                Action = new HelpAction
+                Action = new CustomHelpAction
                 {
                     Builder = helpBuilder
                 }
@@ -317,7 +317,7 @@ public void Argument_can_fallback_to_default_when_customizing(
 
             command.Options.Add(new HelpOption
             {
-                Action = new HelpAction
+                Action = new CustomHelpAction
                 {
                     Builder = helpBuilder
                 }
@@ -336,11 +336,20 @@ public void Individual_symbols_can_be_customized()
             var option = new Option<int>("-x") { Description = "The default option description" };
             var argument = new Argument<int>("int-value") { Description = "The default argument description" };
 
-            var rootCommand = new RootCommand
+            CustomHelpAction helpAction = new();
+            helpAction.Builder.CustomizeSymbol(subcommand, secondColumnText: "The custom command description");
+            helpAction.Builder.CustomizeSymbol(option, secondColumnText: "The custom option description");
+            helpAction.Builder.CustomizeSymbol(argument, secondColumnText: "The custom argument description");
+            
+            var rootCommand = new Command("name")
             {
                 subcommand,
                 option,
                 argument,
+                new HelpOption()
+                {
+                    Action = helpAction
+                }
             };
 
             CommandLineConfiguration config = new(rootCommand)
@@ -350,13 +359,6 @@ public void Individual_symbols_can_be_customized()
 
             ParseResult parseResult = rootCommand.Parse("-h", config);
 
-            if (parseResult.Action is HelpAction helpAction)
-            {
-                helpAction.Builder.CustomizeSymbol(subcommand, secondColumnText: "The custom command description");
-                helpAction.Builder.CustomizeSymbol(option, secondColumnText: "The custom option description");
-                helpAction.Builder.CustomizeSymbol(argument, secondColumnText: "The custom argument description");
-            }
-
             parseResult.Invoke();
 
             config.Output
@@ -370,18 +372,16 @@ public void Individual_symbols_can_be_customized()
         [Fact]
         public void Help_sections_can_be_replaced()
         {
-            CommandLineConfiguration config = new(new RootCommand())
+            CustomHelpAction helpAction = new();
+            helpAction.Builder.CustomizeLayout(CustomLayout);
+
+            CommandLineConfiguration config = new(new Command("name") { new HelpOption() {  Action = helpAction} })
             {
                 Output = new StringWriter()
             };
 
             ParseResult parseResult = config.Parse("-h");
 
-            if (parseResult.Action is HelpAction helpAction)
-            {
-                helpAction.Builder.CustomizeLayout(CustomLayout);
-            }
-
             parseResult.Invoke();
 
             config.Output.ToString().Should().Be($"one{NewLine}{NewLine}two{NewLine}{NewLine}three{NewLine}{NewLine}");
@@ -397,20 +397,18 @@ IEnumerable<Func<HelpContext, bool>> CustomLayout(HelpContext _)
         [Fact]
         public void Help_sections_can_be_supplemented()
         {
-            CommandLineConfiguration config = new(new RootCommand("hello"))
+            CustomHelpAction helpAction = new();
+            helpAction.Builder.CustomizeLayout(CustomLayout);
+
+            CommandLineConfiguration config = new(new Command("hello") { new HelpOption() { Action = helpAction } })
             {
                 Output = new StringWriter(),
             };
 
-            var defaultHelp = GetDefaultHelp(config.RootCommand);
+            var defaultHelp = GetDefaultHelp(new Command("hello"));
 
             ParseResult parseResult = config.Parse("-h");
 
-            if (parseResult.Action is HelpAction helpAction)
-            {
-                helpAction.Builder.CustomizeLayout(CustomLayout);
-            }
-
             parseResult.Invoke();
 
             var output = config.Output.ToString();
@@ -444,7 +442,7 @@ public void Layout_can_be_composed_dynamically_based_on_context()
                 commandWithCustomHelp
             };
 
-            command.Options.OfType<HelpOption>().Single().Action = new HelpAction
+            command.Options.OfType<HelpOption>().Single().Action = new CustomHelpAction
             {
                 Builder = helpBuilder
             };
@@ -480,7 +478,7 @@ public void Help_default_sections_can_be_wrapped()
                 },
                 new HelpOption
                 {
-                    Action = new HelpAction
+                    Action = new CustomHelpAction
                     {
                         Builder = new HelpBuilder(30)
                     }
@@ -509,19 +507,17 @@ public void Help_default_sections_can_be_wrapped()
         [Fact]
         public void Help_customized_sections_can_be_wrapped()
         {
-            CommandLineConfiguration config = new(new RootCommand())
+            CustomHelpAction helpAction = new();
+            helpAction.Builder = new HelpBuilder(10);
+            helpAction.Builder.CustomizeLayout(CustomLayout);
+
+            CommandLineConfiguration config = new(new Command("name") { new HelpOption() { Action = helpAction } })
             {
                 Output = new StringWriter()
             };
 
             ParseResult parseResult = config.Parse("-h");
 
-            if (parseResult.Action is HelpAction helpAction)
-            {
-                helpAction.Builder = new HelpBuilder(10);
-                helpAction.Builder.CustomizeLayout(CustomLayout);
-            }
-
             parseResult.Invoke();
 
             string result = config.Output.ToString();
diff --git a/src/System.CommandLine.Tests/HelpOptionTests.cs b/src/System.CommandLine.Tests/HelpOptionTests.cs
index 531a23d1fa..401656ce0c 100644
--- a/src/System.CommandLine.Tests/HelpOptionTests.cs
+++ b/src/System.CommandLine.Tests/HelpOptionTests.cs
@@ -3,6 +3,7 @@
 
 using FluentAssertions;
 using System.CommandLine.Help;
+using System.CommandLine.Invocation;
 using System.CommandLine.Tests.Utility;
 using System.IO;
 using System.Threading.Tasks;
@@ -186,4 +187,95 @@ public async Task Help_option_with_custom_aliases_does_not_recognize_default_ali
 
         config.Output.ToString().Should().NotContain(helpAlias);
     }
+
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void The_users_can_provide_usage_examples(bool subcommand)
+    {
+        HelpOption helpOption = new();
+        helpOption.Action = new CustomizedHelpAction(helpOption);
+
+        RootCommand rootCommand = new();
+        rootCommand.Options.Clear();
+        rootCommand.Options.Add(helpOption);
+        rootCommand.Subcommands.Add(new Command("subcommand")
+        {
+            new Option<string>("-x")
+            {
+                Description = "An example option."
+            }
+        });
+
+        TextWriter output = new StringWriter();
+        CommandLineConfiguration config = new(rootCommand)
+        {
+            Output = output
+        };
+
+        var result = subcommand ? config.Parse("subcommand -h") : config.Parse("-h");
+
+        result.Invoke();
+
+        if (subcommand)
+        {
+            output.ToString().Should().Contain(CustomizedHelpAction.CustomUsageText);
+        }
+        else
+        {
+            output.ToString().Should().NotContain(CustomizedHelpAction.CustomUsageText);
+        }
+    }
+
+    [Fact]
+    public void The_users_can_print_help_output_of_a_subcommand()
+    {
+        const string RootDescription = "This is a custom root description.";
+        const string SubcommandDescription = "This is a custom subcommand description.";
+        RootCommand rootCommand = new(RootDescription);
+        Command subcommand = new("subcommand", SubcommandDescription)
+        {
+            new Option<string>("-x")
+            {
+                Description = "An example option."
+            }
+        };
+        rootCommand.Subcommands.Add(subcommand);
+
+        TextWriter output = new StringWriter();
+        CommandLineConfiguration config = new(subcommand)
+        {
+            Output = output
+        };
+
+        subcommand.Parse("--help", config).Invoke();
+
+        output.ToString().Should().Contain(SubcommandDescription);
+        output.ToString().Should().NotContain(RootDescription);
+    }
+
+    private sealed class CustomizedHelpAction : SynchronousCommandLineAction
+    {
+        internal const string CustomUsageText = "This is custom command usage example.";
+
+        private readonly HelpAction _helpAction;
+
+        public CustomizedHelpAction(HelpOption helpOption)
+        {
+            _helpAction = (HelpAction)helpOption.Action;
+        }
+
+        public override int Invoke(ParseResult parseResult)
+        {
+            _helpAction.Invoke(parseResult);
+
+            if (parseResult.CommandResult.Command.Name == "subcommand")
+            {
+                var output = parseResult.Configuration.Output;
+                output.WriteLine(CustomUsageText);
+            }
+            
+            return 0;
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/System.CommandLine.Tests/System.CommandLine.Tests.csproj b/src/System.CommandLine.Tests/System.CommandLine.Tests.csproj
index 7569a272b6..db582f0b23 100644
--- a/src/System.CommandLine.Tests/System.CommandLine.Tests.csproj
+++ b/src/System.CommandLine.Tests/System.CommandLine.Tests.csproj
@@ -4,6 +4,7 @@
     <TargetFrameworks>$(TargetFrameworkForNETSDK);$(NetFrameworkCurrent)</TargetFrameworks>
     <GenerateProgramFile>false</GenerateProgramFile>
     <DefaultExcludesInProjectFolder>$(DefaultExcludesInProjectFolder);TestApps\**</DefaultExcludesInProjectFolder>
+    <NoWarn>$(NoWarn);CS8632</NoWarn> <!-- Suppress nullable warning for files included as links -->
   </PropertyGroup>
   
   <ItemGroup>   
@@ -17,6 +18,11 @@
     <Compile Include="..\System.CommandLine.Suggest\DotnetMuxer.cs" Link="Utility\DotnetMuxer.cs" />
     <Compile Include="..\System.CommandLine\LocalizationResources.cs" Link="LocalizationResources.cs" />
     <Compile Include="..\System.CommandLine\Properties\Resources.Designer.cs" Link="Properties\Resources.Designer.cs" />
+    <Compile Include="..\System.CommandLine\Help\HelpBuilder.cs" Link="Help\HelpBuilder.cs" />
+    <Compile Include="..\System.CommandLine\Help\HelpBuilder.Default.cs" Link="Help\HelpBuilder.Default.cs" />
+    <Compile Include="..\System.CommandLine\Help\HelpBuilderExtensions.cs" Link="Help\HelpBuilderExtensions" />
+    <Compile Include="..\System.CommandLine\Help\HelpContext.cs" Link="Help\HelpContext.cs" />
+    <Compile Include="..\System.CommandLine\Help\TwoColumnHelpRow.cs" Link="Help\TwoColumnHelpRow.cs" />
   </ItemGroup>
   
   <ItemGroup>
diff --git a/src/System.CommandLine/EnumerableExtensions.cs b/src/System.CommandLine/EnumerableExtensions.cs
index 2aecce2477..72018aaa38 100644
--- a/src/System.CommandLine/EnumerableExtensions.cs
+++ b/src/System.CommandLine/EnumerableExtensions.cs
@@ -34,18 +34,5 @@ internal static IEnumerable<T> FlattenBreadthFirst<T>(
                 yield return current;
             }
         }
-
-        internal static IEnumerable<T> RecurseWhileNotNull<T>(
-            this T? source,
-            Func<T, T?> next)
-            where T : class
-        {
-            while (source is not null)
-            {
-                yield return source;
-
-                source = next(source);
-            }
-        }
     }
 }
\ No newline at end of file
diff --git a/src/System.CommandLine/Help/HelpOptionAction.cs b/src/System.CommandLine/Help/HelpAction.cs
similarity index 87%
rename from src/System.CommandLine/Help/HelpOptionAction.cs
rename to src/System.CommandLine/Help/HelpAction.cs
index 147b9b0981..7658ddeaad 100644
--- a/src/System.CommandLine/Help/HelpOptionAction.cs
+++ b/src/System.CommandLine/Help/HelpAction.cs
@@ -12,7 +12,7 @@ public sealed class HelpAction : SynchronousCommandLineAction
         /// <summary>
         /// Specifies an <see cref="Builder"/> to be used to format help output when help is requested.
         /// </summary>
-        public HelpBuilder Builder
+        internal HelpBuilder Builder
         {
             get => _builder ??= new HelpBuilder(Console.IsOutputRedirected ? int.MaxValue : Console.WindowWidth);
             set => _builder = value ?? throw new ArgumentNullException(nameof(value));
@@ -25,8 +25,7 @@ public override int Invoke(ParseResult parseResult)
 
             var helpContext = new HelpContext(Builder,
                                               parseResult.CommandResult.Command,
-                                              output,
-                                              parseResult);
+                                              output);
 
             Builder.Write(helpContext);
 
diff --git a/src/System.CommandLine/Help/HelpBuilder.Default.cs b/src/System.CommandLine/Help/HelpBuilder.Default.cs
index 64591f9ec3..0325a44402 100644
--- a/src/System.CommandLine/Help/HelpBuilder.Default.cs
+++ b/src/System.CommandLine/Help/HelpBuilder.Default.cs
@@ -4,12 +4,11 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.CommandLine.Completions;
-using System.CommandLine.Parsing;
 using System.Linq;
 
 namespace System.CommandLine.Help;
 
-public partial class HelpBuilder
+internal partial class HelpBuilder
 {
     /// <summary>
     /// Provides default formatting for help output.
@@ -19,25 +18,23 @@ public static class Default
         /// <summary>
         /// Gets an argument's default value to be displayed in help.
         /// </summary>
-        /// <param name="argument">The argument to get the default value for.</param>
-        public static string GetArgumentDefaultValue(Argument argument)
+        /// <param name="parameter">The argument or option to get the default value for.</param>
+        public static string GetArgumentDefaultValue(Symbol parameter)
         {
-            if (argument.HasDefaultValue)
+            return parameter switch
             {
-                if (argument.GetDefaultValue() is { } defaultValue)
-                {
-                    if (defaultValue is IEnumerable enumerable and not string)
-                    {
-                        return string.Join("|", enumerable.OfType<object>().ToArray());
-                    }
-                    else
-                    {
-                        return defaultValue.ToString() ?? "";
-                    }
-                }
-            }
+                Argument argument => argument.HasDefaultValue ? ToString(argument.GetDefaultValue()) : "",
+                Option option => option.HasDefaultValue ? ToString(option.GetDefaultValue()) : "",
+                _ => throw new InvalidOperationException("Symbol must be an Argument or Option.")
+            };
 
-            return string.Empty;
+            static string ToString(object? value) => value switch
+            {
+                null => string.Empty,
+                string str => str,
+                IEnumerable enumerable => string.Join("|", enumerable.Cast<object>()),
+                _ => value.ToString() ?? string.Empty
+            };
         }
 
         /// <summary>
@@ -48,29 +45,39 @@ public static string GetArgumentDefaultValue(Argument argument)
         /// <summary>
         /// Gets the usage title for an argument (for example: <c>&lt;value&gt;</c>, typically used in the first column text in the arguments usage section, or within the synopsis.
         /// </summary>
-        public static string GetArgumentUsageLabel(Argument argument)
+        public static string GetArgumentUsageLabel(Symbol parameter)
         {
-            // Argument.HelpName is always first choice
-            if (!string.IsNullOrWhiteSpace(argument.HelpName))
+            // By default Option.Name == Argument.Name, don't repeat it
+            return parameter switch
             {
-                return $"<{argument.HelpName}>";
-            }
-            else if (!argument.IsBoolean() && argument.CompletionSources.Count > 0)
+                Argument argument => GetUsageLabel(argument.HelpName, argument.ValueType, argument.CompletionSources, argument) ?? $"<{argument.Name}>",
+                Option option => GetUsageLabel(option.HelpName, option.ValueType, option.CompletionSources, option) ?? "",
+                _ => throw new InvalidOperationException()
+            };
+
+            static string? GetUsageLabel(string? helpName, Type valueType, List<Func<CompletionContext, IEnumerable<CompletionItem>>> completionSources, Symbol symbol)
             {
-                IEnumerable<string> completions = argument
-                    .GetCompletions(CompletionContext.Empty)
-                    .Select(item => item.Label);
+                // Argument.HelpName is always first choice
+                if (!string.IsNullOrWhiteSpace(helpName))
+                {
+                    return $"<{helpName}>";
+                }
+                else if (!(valueType == typeof(bool) || valueType == typeof(bool?)) && completionSources.Count > 0)
+                {
+                    IEnumerable<string> completions = symbol
+                        .GetCompletions(CompletionContext.Empty)
+                        .Select(item => item.Label);
 
-                string joined = string.Join("|", completions);
+                    string joined = string.Join("|", completions);
 
-                if (!string.IsNullOrEmpty(joined))
-                {
-                    return $"<{joined}>";
+                    if (!string.IsNullOrEmpty(joined))
+                    {
+                        return $"<{joined}>";
+                    }
                 }
-            }
 
-            // By default Option.Name == Argument.Name, don't repeat it
-            return argument.FirstParent?.Symbol is not Option ? $"<{argument.Name}>" : "";
+                return null;
+            }
         }
 
         /// <summary>
@@ -79,13 +86,13 @@ public static string GetArgumentUsageLabel(Argument argument)
         /// <param name="symbol">The symbol to get a help item for.</param>
         /// <returns>Text to display.</returns>
         public static string GetCommandUsageLabel(Command symbol)
-            => GetIdentifierSymbolUsageLabel(symbol, symbol._aliases);
+            => GetIdentifierSymbolUsageLabel(symbol, symbol.Aliases);
 
         /// <inheritdoc cref="GetCommandUsageLabel(Command)"/>
         public static string GetOptionUsageLabel(Option symbol)
-            => GetIdentifierSymbolUsageLabel(symbol, symbol._aliases);
+            => GetIdentifierSymbolUsageLabel(symbol, symbol.Aliases);
 
-        private static string GetIdentifierSymbolUsageLabel(Symbol symbol, AliasSet? aliasSet)
+        private static string GetIdentifierSymbolUsageLabel(Symbol symbol, ICollection<string>? aliasSet)
         {
             var aliases =  aliasSet is null
                 ? new [] { symbol.Name }
@@ -99,7 +106,7 @@ private static string GetIdentifierSymbolUsageLabel(Symbol symbol, AliasSet? ali
 
             var firstColumnText = string.Join(", ", aliases);
 
-            foreach (var argument in symbol.Arguments())
+            foreach (var argument in symbol.GetParameters())
             {
                 if (!argument.Hidden)
                 {
@@ -185,18 +192,14 @@ public static Func<HelpContext, bool> OptionsSection() =>
             {
                 List<TwoColumnHelpRow> optionRows = new();
                 bool addedHelpOption = false;
-
-                if (ctx.Command.HasOptions)
+                foreach (Option option in ctx.Command.Options)
                 {
-                    foreach (Option option in ctx.Command.Options)
+                    if (!option.Hidden)
                     {
-                        if (!option.Hidden)
+                        optionRows.Add(ctx.HelpBuilder.GetTwoColumnRow(option, ctx));
+                        if (option is HelpOption)
                         {
-                            optionRows.Add(ctx.HelpBuilder.GetTwoColumnRow(option, ctx));
-                            if (option is HelpOption)
-                            {
-                                addedHelpOption = true;
-                            }
+                            addedHelpOption = true;
                         }
                     }
                 }
@@ -205,12 +208,11 @@ public static Func<HelpContext, bool> OptionsSection() =>
                 while (current is not null)
                 {
                     Command? parentCommand = null;
-                    SymbolNode? parent = current.FirstParent;
-                    while (parent is not null)
+                    foreach (Symbol parent in current.Parents)
                     {
-                        if ((parentCommand = parent.Symbol as Command) is not null)
+                        if ((parentCommand = parent as Command) is not null)
                         {
-                            if (parentCommand.HasOptions)
+                            if (parentCommand.Options.Any())
                             {
                                 foreach (var option in parentCommand.Options)
                                 {
@@ -227,7 +229,6 @@ public static Func<HelpContext, bool> OptionsSection() =>
 
                             break;
                         }
-                        parent = parent.Next;
                     }
                     current = parentCommand;
                 }
diff --git a/src/System.CommandLine/Help/HelpBuilder.cs b/src/System.CommandLine/Help/HelpBuilder.cs
index 483a54ee05..2a035e24f4 100644
--- a/src/System.CommandLine/Help/HelpBuilder.cs
+++ b/src/System.CommandLine/Help/HelpBuilder.cs
@@ -11,7 +11,7 @@ namespace System.CommandLine.Help
     /// <summary>
     /// Formats output to be shown to users to describe how to use a command line tool.
     /// </summary>
-    public partial class HelpBuilder 
+    internal partial class HelpBuilder 
     {
         private const string Indent = "  ";
 
@@ -91,6 +91,30 @@ public void CustomizeLayout(Func<HelpContext, IEnumerable<Func<HelpContext, bool
             _getLayout = getLayout ?? throw new ArgumentNullException(nameof(getLayout));
         }
 
+        /// <summary>
+        /// Specifies custom help details for a specific symbol.
+        /// </summary>
+        /// <param name="symbol">The symbol to customize the help details for.</param>
+        /// <param name="firstColumnText">A delegate to display the first help column (typically name and usage information).</param>
+        /// <param name="secondColumnText">A delegate to display second help column (typically the description).</param>
+        /// <param name="defaultValue">The displayed default value for the symbol.</param>
+        public void CustomizeSymbol(
+            Symbol symbol,
+            string? firstColumnText = null,
+            string? secondColumnText = null,
+            string? defaultValue = null)
+        {
+            CustomizeSymbol(symbol, _ => firstColumnText, _ => secondColumnText, _ => defaultValue);
+        }
+
+        /// <summary>
+        /// Writes help output for the specified command.
+        /// </summary>
+        public void Write(Command command, TextWriter writer)
+        {
+            Write(new HelpContext(this, command, writer));
+        }
+
         private string GetUsage(Command command)
         {
             return string.Join(" ", GetUsageParts().Where(x => !string.IsNullOrWhiteSpace(x)));
@@ -108,25 +132,25 @@ IEnumerable<string> GetUsageParts()
                 {
                     if (!displayOptionTitle)
                     {
-                        displayOptionTitle = parentCommand.HasOptions && parentCommand.Options.Any(x => x.Recursive && !x.Hidden);
+                        displayOptionTitle = parentCommand.Options.Any(x => x.Recursive && !x.Hidden);
                     }
 
                     yield return parentCommand.Name;
 
-                    if (parentCommand.HasArguments)
+                    if (parentCommand.Arguments.Any())
                     {
                         yield return FormatArgumentUsage(parentCommand.Arguments);
                     }
                 }
 
-                var hasCommandWithHelp = command.HasSubcommands && command.Subcommands.Any(x => !x.Hidden);
+                var hasCommandWithHelp = command.Subcommands.Any(x => !x.Hidden);
 
                 if (hasCommandWithHelp)
                 {
                     yield return LocalizationResources.HelpUsageCommand();
                 }
 
-                displayOptionTitle = displayOptionTitle || (command.HasOptions && command.Options.Any(x => !x.Hidden));
+                displayOptionTitle = displayOptionTitle || (command.Options.Any(x => !x.Hidden));
                 
                 if (displayOptionTitle)
                 {
@@ -441,8 +465,8 @@ TwoColumnHelpRow GetCommandArgumentRow(Argument argument)
 
             string GetSymbolDefaultValue(Symbol symbol)
             {
-                IList<Argument> arguments = symbol.Arguments();
-                var defaultArguments = arguments.Where(x => !x.Hidden && x.HasDefaultValue).ToArray();
+                var arguments = symbol.GetParameters();
+                var defaultArguments = arguments.Where(x => !x.Hidden && (x is Argument { HasDefaultValue: true } || x is Option { HasDefaultValue: true })).ToArray();
 
                 if (defaultArguments.Length == 0) return "";
 
@@ -455,13 +479,13 @@ string GetSymbolDefaultValue(Symbol symbol)
 
         private string GetArgumentDefaultValue(
             Symbol parent,
-            Argument argument,
+            Symbol parameter,
             bool displayArgumentName,
             HelpContext context)
         {
             string label = displayArgumentName 
                               ? LocalizationResources.HelpArgumentDefaultValueLabel() 
-                              : argument.Name;
+                              : parameter.Name;
 
             string? displayedDefaultValue = null;
 
@@ -472,14 +496,14 @@ private string GetArgumentDefaultValue(
                 {
                     displayedDefaultValue = parentDefaultValue;
                 }
-                else if (_customizationsBySymbol.TryGetValue(argument, out customization) &&
+                else if (_customizationsBySymbol.TryGetValue(parameter, out customization) &&
                          customization.GetDefaultValue?.Invoke(context) is { } ownDefaultValue)
                 {
                     displayedDefaultValue = ownDefaultValue;
                 }
             }
 
-            displayedDefaultValue ??= Default.GetArgumentDefaultValue(argument);
+            displayedDefaultValue ??= Default.GetArgumentDefaultValue(parameter);
 
             if (string.IsNullOrWhiteSpace(displayedDefaultValue))
             {
diff --git a/src/System.CommandLine/Help/HelpBuilderExtensions.cs b/src/System.CommandLine/Help/HelpBuilderExtensions.cs
index 992119a375..a130f13220 100644
--- a/src/System.CommandLine/Help/HelpBuilderExtensions.cs
+++ b/src/System.CommandLine/Help/HelpBuilderExtensions.cs
@@ -1,34 +1,60 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
-using System.IO;
+using System.Collections.Generic;
 
 namespace System.CommandLine.Help
 {
-    public partial class HelpBuilder
+    internal static class HelpBuilderExtensions
     {
-        /// <summary>
-        /// Specifies custom help details for a specific symbol.
-        /// </summary>
-        /// <param name="symbol">The symbol to customize the help details for.</param>
-        /// <param name="firstColumnText">A delegate to display the first help column (typically name and usage information).</param>
-        /// <param name="secondColumnText">A delegate to display second help column (typically the description).</param>
-        /// <param name="defaultValue">The displayed default value for the symbol.</param>
-        public void CustomizeSymbol(
-            Symbol symbol,
-            string? firstColumnText = null,
-            string? secondColumnText = null,
-            string? defaultValue = null)
+        internal static IEnumerable<Symbol> GetParameters(this Symbol symbol)
         {
-            CustomizeSymbol(symbol, _ => firstColumnText, _ => secondColumnText, _ => defaultValue);
+            switch (symbol)
+            {
+                case Option option:
+                    yield return option;
+                    yield break;
+                case Command command:
+                    foreach (var argument in command.Arguments)
+                    {
+                        yield return argument;
+                    }
+                    yield break;
+                case Argument argument:
+                    yield return argument;
+                    yield break;
+                default:
+                    throw new NotSupportedException();
+            }
         }
 
-        /// <summary>
-        /// Writes help output for the specified command.
-        /// </summary>
-        public void Write(Command command, TextWriter writer)
+        internal static (string? Prefix, string Alias) SplitPrefix(this string rawAlias)
         {
-            Write(new HelpContext(this, command, writer));
+            if (rawAlias[0] == '/')
+            {
+                return ("/", rawAlias.Substring(1));
+            }
+            else if (rawAlias[0] == '-')
+            {
+                if (rawAlias.Length > 1 && rawAlias[1] == '-')
+                {
+                    return ("--", rawAlias.Substring(2));
+                }
+
+                return ("-", rawAlias.Substring(1));
+            }
+
+            return (null, rawAlias);
+        }
+
+        internal static IEnumerable<T> RecurseWhileNotNull<T>(this T? source, Func<T, T?> next) where T : class
+        {
+            while (source is not null)
+            {
+                yield return source;
+
+                source = next(source);
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/src/System.CommandLine/Help/HelpContext.cs b/src/System.CommandLine/Help/HelpContext.cs
index a9935941da..6162933843 100644
--- a/src/System.CommandLine/Help/HelpContext.cs
+++ b/src/System.CommandLine/Help/HelpContext.cs
@@ -8,22 +8,19 @@ namespace System.CommandLine.Help
     /// <summary>
     /// Supports formatting command line help.
     /// </summary>
-    public class HelpContext
+    internal class HelpContext
     {
         /// <param name="helpBuilder">The current help builder.</param>
         /// <param name="command">The command for which help is being formatted.</param>
         /// <param name="output">A text writer to write output to.</param>
-        /// <param name="parseResult">The result of the current parse operation.</param>
         public HelpContext(
             HelpBuilder helpBuilder,
             Command command,
-            TextWriter output,
-            ParseResult? parseResult = null)
+            TextWriter output)
         {
             HelpBuilder = helpBuilder ?? throw new ArgumentNullException(nameof(helpBuilder));
             Command = command ?? throw new ArgumentNullException(nameof(command));
             Output = output ?? throw new ArgumentNullException(nameof(output));
-            ParseResult = parseResult ?? ParseResult.Empty();
         }
 
         /// <summary>
@@ -31,11 +28,6 @@ public HelpContext(
         /// </summary>
         public HelpBuilder HelpBuilder { get; }
 
-        /// <summary>
-        /// The result of the current parse operation.
-        /// </summary>
-        public ParseResult ParseResult { get; }
-
         /// <summary>
         /// The command for which help is being formatted.
         /// </summary>
diff --git a/src/System.CommandLine/Help/TwoColumnHelpRow.cs b/src/System.CommandLine/Help/TwoColumnHelpRow.cs
index 361b0e7af9..fab0958337 100644
--- a/src/System.CommandLine/Help/TwoColumnHelpRow.cs
+++ b/src/System.CommandLine/Help/TwoColumnHelpRow.cs
@@ -8,7 +8,7 @@ namespace System.CommandLine.Help
     /// <summary>
     /// Provides details about an item to be formatted to output in order to display two-column command line help.
     /// </summary>
-    public class TwoColumnHelpRow : IEquatable<TwoColumnHelpRow?>
+    internal class TwoColumnHelpRow : IEquatable<TwoColumnHelpRow?>
     {
         /// <param name="firstColumnText">The name and invocation details, typically displayed in the first help column.</param>
         /// <param name="secondColumnText">The description of a symbol, typically displayed in the second help column.</param>
diff --git a/src/System.CommandLine/Option.cs b/src/System.CommandLine/Option.cs
index c6abaf3725..c9d81062e7 100644
--- a/src/System.CommandLine/Option.cs
+++ b/src/System.CommandLine/Option.cs
@@ -137,5 +137,11 @@ public override IEnumerable<CompletionItem> GetCompletions(CompletionContext con
                    .OrderBy(item => item.SortText.IndexOfCaseInsensitive(context.WordToComplete))
                    .ThenBy(symbol => symbol.Label, StringComparer.OrdinalIgnoreCase);
         }
+
+        /// <summary>
+        /// Gets the default value for the option.
+        /// </summary>
+        /// <returns>Returns the default value for the option, if defined. Null otherwise.</returns>
+        public object? GetDefaultValue() => Argument.GetDefaultValue();
     }
 }
diff --git a/src/System.CommandLine/ParseResult.cs b/src/System.CommandLine/ParseResult.cs
index 92b209f93a..9b476782e0 100644
--- a/src/System.CommandLine/ParseResult.cs
+++ b/src/System.CommandLine/ParseResult.cs
@@ -175,6 +175,14 @@ CommandLineText is null
         public SymbolResult? GetResult(Symbol symbol)
             => _rootCommandResult.SymbolResultTree.TryGetValue(symbol, out SymbolResult? result) ? result : null;
 
+        /// <summary>
+        /// Finds a result for a symbol having the specified name anywhere in the parse tree.
+        /// </summary>
+        /// <param name="name">The name of the symbol for which to find a result.</param>
+        /// <returns>An symbol result if the argument was matched by the parser or has a default value; otherwise, <c>null</c>.</returns>
+        public SymbolResult? GetResult(string name) =>
+            _rootCommandResult.SymbolResultTree.GetResult(name);
+
         /// <summary>
         /// Gets completions based on a given parse result.
         /// </summary>
diff --git a/src/System.CommandLine/Parsing/StringExtensions.cs b/src/System.CommandLine/Parsing/StringExtensions.cs
index 8749e7eef1..b1f7b63ad2 100644
--- a/src/System.CommandLine/Parsing/StringExtensions.cs
+++ b/src/System.CommandLine/Parsing/StringExtensions.cs
@@ -24,25 +24,6 @@ internal static int IndexOfCaseInsensitive(
                                 value,
                                 CompareOptions.OrdinalIgnoreCase);
 
-        internal static (string? Prefix, string Alias) SplitPrefix(this string rawAlias)
-        {
-            if (rawAlias[0] == '/')
-            {
-                return ("/", rawAlias.Substring(1));
-            }
-            else if (rawAlias[0] == '-')
-            {
-                if (rawAlias.Length > 1 && rawAlias[1] == '-')
-                {
-                    return ("--", rawAlias.Substring(2));
-                }
-
-                return ("-", rawAlias.Substring(1));
-            }
-
-            return (null, rawAlias);
-        }
-
         // this method is not returning a Value Tuple or a dedicated type to avoid JITting
         internal static void Tokenize(
             this IReadOnlyList<string> args,
diff --git a/src/System.CommandLine/Parsing/SymbolResultTree.cs b/src/System.CommandLine/Parsing/SymbolResultTree.cs
index e287b66494..4778c4093e 100644
--- a/src/System.CommandLine/Parsing/SymbolResultTree.cs
+++ b/src/System.CommandLine/Parsing/SymbolResultTree.cs
@@ -108,7 +108,7 @@ private void PopulateSymbolsByName(Command command)
             {
                 for (var i = 0; i < command.Arguments.Count; i++)
                 {
-                    AddToSymbolsByName(command.Arguments[i]);
+                    AddToSymbolsByName(command.Arguments[i], command);
                 }
             }
 
@@ -116,7 +116,7 @@ private void PopulateSymbolsByName(Command command)
             {
                 for (var i = 0; i < command.Options.Count; i++)
                 {
-                    AddToSymbolsByName(command.Options[i]);
+                    AddToSymbolsByName(command.Options[i], command);
                 }
             }
 
@@ -125,30 +125,35 @@ private void PopulateSymbolsByName(Command command)
                 for (var i = 0; i < command.Subcommands.Count; i++)
                 {
                     var childCommand = command.Subcommands[i];
-                    AddToSymbolsByName(childCommand);
+                    AddToSymbolsByName(childCommand, command);
                     PopulateSymbolsByName(childCommand);
                 }
             }
 
-            void AddToSymbolsByName(Symbol symbol)
+            void AddToSymbolsByName(Symbol symbol, Command parent)
             {
                 if (_symbolsByName!.TryGetValue(symbol.Name, out var node))
                 {
-                    if (symbol.Name == node.Symbol.Name &&
-                        symbol.FirstParent?.Symbol is { } parent &&
-                        parent == node.Symbol.FirstParent?.Symbol)
+                    var current = node;
+                    do
                     {
-                        throw new InvalidOperationException($"Command {parent.Name} has more than one child named \"{symbol.Name}\".");
-                    }
-
-                    _symbolsByName[symbol.Name] = new(symbol)
+                        // The same symbol can be added to multiple commands and have multiple parents.
+                        // We can't allow for name duplicates within the same command.
+                        if (ReferenceEquals(current.Parent, parent))
+                        {
+                            throw new InvalidOperationException($"Command {parent.Name} has more than one child named \"{symbol.Name}\".");
+                        }
+                        current = current.Next;
+                    } while (current is not null);
+
+                    _symbolsByName[symbol.Name] = new(symbol, parent)
                     {
                         Next = node
                     };
                 }
                 else
                 {
-                    _symbolsByName[symbol.Name] = new(symbol);
+                    _symbolsByName[symbol.Name] = new(symbol, parent);
                 }
             }
         }
diff --git a/src/System.CommandLine/SymbolExtensions.cs b/src/System.CommandLine/SymbolExtensions.cs
deleted file mode 100644
index e73f859638..0000000000
--- a/src/System.CommandLine/SymbolExtensions.cs
+++ /dev/null
@@ -1,34 +0,0 @@
-// Copyright (c) .NET Foundation and contributors. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-using System.Collections.Generic;
-
-namespace System.CommandLine
-{
-    /// <summary>
-    /// Provides extension methods for symbols.
-    /// </summary>
-    internal static class SymbolExtensions
-    {
-        internal static IList<Argument> Arguments(this Symbol symbol)
-        {
-            switch (symbol)
-            {
-                case Option option:
-                    return new[]
-                    {
-                        option.Argument
-                    };
-                case Command command:
-                    return command.Arguments;
-                case Argument argument:
-                    return new[]
-                    {
-                        argument
-                    };
-                default:
-                    throw new NotSupportedException();
-            }
-        }
-    }
-}
\ No newline at end of file
diff --git a/src/System.CommandLine/SymbolNode.cs b/src/System.CommandLine/SymbolNode.cs
index f76037fdb5..c415e3c868 100644
--- a/src/System.CommandLine/SymbolNode.cs
+++ b/src/System.CommandLine/SymbolNode.cs
@@ -5,10 +5,16 @@ namespace System.CommandLine
 {
     internal sealed class SymbolNode
     {
-        internal SymbolNode(Symbol symbol) => Symbol = symbol;
+        internal SymbolNode(Symbol symbol, Command? parent = null)
+        {
+            Symbol = symbol;
+            Parent = parent;
+        }
 
         internal Symbol Symbol { get; }
 
+        internal Command? Parent { get; }
+
         internal SymbolNode? Next { get; set; }
     }
 }
\ No newline at end of file