diff --git a/EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeCommand.cs b/EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeCommand.cs
index 28f4ea86..a0b4afab 100644
--- a/EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeCommand.cs
+++ b/EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeCommand.cs
@@ -130,10 +130,27 @@ public record CreateEnvelopeCommand : IRequest<EnvelopeDto?>
     public bool UseSQLExecutor { get; set; } = true;
 }
 
+/// <summary>
+/// 
+/// </summary>
+/// <param name="DataAsBase64"></param>
 public record CreateEnvelopeDocumentDto(string DataAsBase64);
 
+/// <summary>
+/// 
+/// </summary>
+/// <param name="X"></param>
+/// <param name="Y"></param>
+/// <param name="Page"></param>
 public record CreateEnvelopeFieldDto(double X, double Y, int Page);
 
+/// <summary>
+/// 
+/// </summary>
+/// <param name="EmailAddress"></param>
+/// <param name="Name"></param>
+/// <param name="PhoneNumber"></param>
+/// <param name="Fields"></param>
 public record CreateEnvelopeReceiverDto(
     string EmailAddress,
     string? Name,
diff --git a/EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeCommandHandler.cs b/EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeCommandHandler.cs
index 888d5b20..5097fda5 100644
--- a/EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeCommandHandler.cs
+++ b/EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeCommandHandler.cs
@@ -49,6 +49,7 @@ public class CreateEnvelopeCommandHandler : IRequestHandler<CreateEnvelopeComman
 
     private SignatureFieldParams SignatureFieldParams => _provider.GetRequiredService<IOptionsMonitor<SignatureFieldParams>>().CurrentValue;
 
+    [Obsolete("Use IConfigService instead.")]
     private IConfigService ConfigService => _provider.GetRequiredService<IConfigService>();
 
     private IMediator Mediator => _provider.GetRequiredService<IMediator>();
diff --git a/EnvelopeGenerator.Tests/Application/Fake.cs b/EnvelopeGenerator.Tests/Application/Fake.cs
index 3d3265ea..8c0d8f04 100644
--- a/EnvelopeGenerator.Tests/Application/Fake.cs
+++ b/EnvelopeGenerator.Tests/Application/Fake.cs
@@ -215,7 +215,7 @@ public static class Extensions
         Message = faker.Lorem.Paragraph(faker.Random.Number(2, 5)),
         TfaEnabled = tfaEnabled,
         AddedWhen = DateTime.Now,
-        CertificationType = (int)CertificationType.AdvancedElectronicSignature,
+        CertificationType = CertificationType.AdvancedElectronicSignature,
         UseAccessCode = false,
         ContractType = (int)ContractType.Contract,
         Language = "de",
diff --git a/EnvelopeGenerator.Tests/EnvelopeGenerator.Tests.csproj b/EnvelopeGenerator.Tests/EnvelopeGenerator.Tests.csproj
index c0c01185..0c155811 100644
--- a/EnvelopeGenerator.Tests/EnvelopeGenerator.Tests.csproj
+++ b/EnvelopeGenerator.Tests/EnvelopeGenerator.Tests.csproj
@@ -71,10 +71,12 @@
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
     <ProjectReference Include="..\EnvelopeGenerator.Infrastructure.Crypt\EnvelopeGenerator.Infrastructure.Crypt.csproj" />
+    <ProjectReference Include="..\EnvelopeGenerator.Infrastructure.Notification\EnvelopeGenerator.Infrastructure.Notification.csproj" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net7.0'">
     <Compile Remove="Application\Crypt\**\*.cs" />
+    <Compile Remove="Infrastructure\**\*.cs" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
diff --git a/EnvelopeGenerator.Tests/Infrastructure/MailTemplatePlaceholderDbTests.cs b/EnvelopeGenerator.Tests/Infrastructure/MailTemplatePlaceholderDbTests.cs
new file mode 100644
index 00000000..4dfd95c3
--- /dev/null
+++ b/EnvelopeGenerator.Tests/Infrastructure/MailTemplatePlaceholderDbTests.cs
@@ -0,0 +1,145 @@
+using System.Text.Json;
+using System.Text.RegularExpressions;
+using EnvelopeGenerator.Infrastructure.Notification;
+using Microsoft.Data.SqlClient;
+
+namespace EnvelopeGenerator.Tests.Infrastructure;
+
+[TestFixture]
+public class MailTemplatePlaceholderDbTests
+{
+    private static readonly Regex PlaceholderPattern = new(@"\[[A-Z0-9_]+\]", RegexOptions.Compiled);
+
+    private static IEnumerable<TestCaseData> DbTemplateCases()
+    {
+        foreach (var template in ReadTemplates())
+        {
+            yield return new TestCaseData(template)
+            {
+                TestName = $"Template_{template.Name}_{template.LangCode}_{template.Guid}"
+            };
+        }
+    }
+
+    [Test]
+    public void Database_contains_templates()
+    {
+        Assert.That(ReadTemplates(), Is.Not.Empty);
+    }
+
+    [TestCaseSource(nameof(DbTemplateCases))]
+    public void Every_placeholder_in_every_db_template_is_replaced(TemplateRow template)
+    {
+        var data = new TemplatePlaceholders();
+
+        var subject = template.Subject.ReplacePlaceholders(data);
+        var body = template.Body.ReplacePlaceholders(data);
+
+        var originalTokens = PlaceholderPattern
+            .Matches(template.Subject + template.Body)
+            .Select(m => m.Value)
+            .Distinct()
+            .ToArray();
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(Unresolved(subject), Is.Empty,
+                $"'{template.Name}' subject has unresolved placeholders.");
+            Assert.That(Unresolved(body), Is.Empty,
+                $"'{template.Name}' body has unresolved placeholders.");
+
+            foreach (var token in originalTokens)
+            {
+                Assert.That(subject + body, Does.Contain(Expected(token)),
+                    $"'{template.Name}' placeholder {token} was not replaced with its value.");
+            }
+        });
+    }
+
+    private static string[] Unresolved(string text)
+        => PlaceholderPattern.Matches(text)
+            .Select(m => m.Value)
+            .Distinct()
+            .ToArray();
+
+    private static string Expected(string token) => $"__{token.Trim('[', ']')}__";
+
+    private static List<TemplateRow> ReadTemplates()
+    {
+        const string sql = "SELECT GUID, NAME, SUBJECT, BODY, LANG_CODE FROM TBSIG_EMAIL_TEMPLATE";
+
+        using var connection = new SqlConnection(ReadConnectionString());
+        connection.Open();
+
+        using var command = new SqlCommand(sql, connection);
+        using var reader = command.ExecuteReader();
+
+        var templates = new List<TemplateRow>();
+        while (reader.Read())
+        {
+            templates.Add(new TemplateRow(
+                reader.GetInt32(0),
+                reader.GetString(1),
+                reader.IsDBNull(2) ? string.Empty : reader.GetString(2),
+                reader.IsDBNull(3) ? string.Empty : reader.GetString(3),
+                reader.IsDBNull(4) ? string.Empty : reader.GetString(4)));
+        }
+
+        return templates;
+    }
+
+    private static string ReadConnectionString()
+    {
+        var directory = new DirectoryInfo(AppContext.BaseDirectory);
+        while (directory is not null && !File.Exists(Path.Combine(directory.FullName, "EnvelopeGenerator.sln")))
+            directory = directory.Parent;
+
+        if (directory is null)
+            throw new InvalidOperationException("Solution root (EnvelopeGenerator.sln) was not found.");
+
+        var settingsPath = Path.Combine(
+            directory.FullName,
+            "EnvelopeGenerator.Server",
+            "EnvelopeGenerator.Server",
+            "appsettings.json");
+
+        using var stream = File.OpenRead(settingsPath);
+        using var document = JsonDocument.Parse(stream, new JsonDocumentOptions
+        {
+            CommentHandling = JsonCommentHandling.Skip,
+            AllowTrailingCommas = true
+        });
+
+        return document.RootElement
+            .GetProperty("ConnectionStrings")
+            .GetProperty("Default")
+            .GetString()
+            ?? throw new InvalidOperationException($"ConnectionStrings:Default is missing in '{settingsPath}'.");
+    }
+
+    public sealed record TemplateRow(int Guid, string Name, string Subject, string Body, string LangCode);
+
+    /// <summary>
+    /// One property per placeholder used by any row in TBSIG_EMAIL_TEMPLATE.
+    /// The sentinel value equals the placeholder name, so a wrong mapping is detected.
+    /// </summary>
+    private sealed class TemplatePlaceholders
+    {
+        public string DocumentProcess { get; set; } = "__DOCUMENT_PROCESS__";
+        public string DocumentTitle { get; set; } = "__DOCUMENT_TITLE__";
+        public string LinkToDocumentText { get; set; } = "__LINK_TO_DOCUMENT_TEXT__";
+        public string LinkToDocument { get; set; } = "__LINK_TO_DOCUMENT__";
+        public string Message { get; set; } = "__MESSAGE__";
+        public string NamePortal { get; set; } = "__NAME_PORTAL__";
+        public string NameReceiver { get; set; } = "__NAME_RECEIVER__";
+        public string NameSender { get; set; } = "__NAME_SENDER__";
+        public string SignatureType { get; set; } = "__SIGNATURE_TYPE__";
+        public string Reason { get; set; } = "__REASON__";
+        public string ReceiverAction { get; set; } = "__RECEIVER_ACTION__";
+        public string FinalAction { get; set; } = "__FINAL_ACTION__";
+        public string FinalStatus { get; set; } = "__FINAL_STATUS__";
+        public string DocumentAccessCode { get; set; } = "__DOCUMENT_ACCESS_CODE__";
+        public string TfaExpiration { get; set; } = "__TFA_EXPIRATION__";
+        public string TfaQrCode { get; set; } = "__TFA_QR_CODE__";
+    }
+}
diff --git a/EnvelopeGenerator.Tests/Infrastructure/ReplacePlaceholderExtensionsTests.cs b/EnvelopeGenerator.Tests/Infrastructure/ReplacePlaceholderExtensionsTests.cs
new file mode 100644
index 00000000..283a6d9b
--- /dev/null
+++ b/EnvelopeGenerator.Tests/Infrastructure/ReplacePlaceholderExtensionsTests.cs
@@ -0,0 +1,478 @@
+using EnvelopeGenerator.Application.Common.Interfaces.Services.Notification;
+using EnvelopeGenerator.Infrastructure.Notification;
+
+namespace EnvelopeGenerator.Tests.Infrastructure;
+
+[TestFixture]
+public class ReplacePlaceholderExtensionsTests
+{
+    #region Naming
+
+    private static IEnumerable<TestCaseData> NamingCases()
+    {
+        yield return Naming<PersonModel>("[FIRST_NAME]");
+        yield return Naming<PersonModel>("[LAST_NAME]");
+        yield return Naming<IdModel>("[ID]");
+        yield return Naming<UpperIdModel>("[ID]");
+        yield return Naming<AcronymModel>("[URL_VALUE]");
+        yield return Naming<AcronymModel>("[HTTP_STATUS_CODE]");
+        yield return Naming<AcronymModel>("[XML_HTTP_REQUEST]");
+        yield return Naming<AcronymModel>("[OTP]");
+        yield return Naming<DigitModel>("[FIELD1]");
+        yield return Naming<DigitModel>("[VALUE2_TEXT]");
+        yield return Naming<DigitModel>("[A1_B2]");
+        yield return Naming<DigitModel>("[NAME2]");
+        yield return Naming<MyUrl2ValueModel>("[MY_URL2_VALUE]");
+        yield return Naming<SingleLetterModel>("[X]");
+        yield return Naming<LowerCaseModel>("[FIRST_NAME]");
+        yield return Naming<SnakeCaseModel>("[FIRST_NAME]");
+        yield return Naming<TfaModel>("[TFA_EXPIRATION]");
+    }
+
+    private static TestCaseData Naming<T>(string placeholder) where T : new()
+        => new(new T(), placeholder)
+        {
+            TestName = $"Placeholder_{typeof(T).Name}_{placeholder.Trim('[', ']')}"
+        };
+
+    [TestCaseSource(nameof(NamingCases))]
+    public void Property_names_are_converted_to_upper_snake_case(object data, string placeholder)
+    {
+        var result = placeholder.ReplacePlaceholders(data);
+
+        Assert.That(result, Is.EqualTo("v"));
+    }
+
+    [Test]
+    [SetCulture("tr-TR")]
+    public void Placeholder_names_are_culture_invariant()
+    {
+        var result = "[INFO]".ReplacePlaceholders(new LowerCaseInfoModel());
+
+        Assert.That(result, Is.EqualTo("v"), "Turkish casing would produce [\u0130NFO]");
+    }
+
+    #endregion
+
+    #region Basic replacement
+
+    [Test]
+    public void Replaces_single_placeholder()
+    {
+        var result = "[FIRST_NAME]".ReplacePlaceholders(new PersonModel { FirstName = "Ada" });
+
+        Assert.That(result, Is.EqualTo("Ada"));
+    }
+
+    [Test]
+    public void Replaces_multiple_placeholders()
+    {
+        var data = new PersonModel { FirstName = "Ada", LastName = "Lovelace" };
+
+        var result = "[FIRST_NAME] [LAST_NAME]".ReplacePlaceholders(data);
+
+        Assert.That(result, Is.EqualTo("Ada Lovelace"));
+    }
+
+    [Test]
+    public void Replaces_all_repeated_occurrences()
+    {
+        var data = new PersonModel { FirstName = "Ada" };
+
+        var result = "[FIRST_NAME]-[FIRST_NAME]-[FIRST_NAME]".ReplacePlaceholders(data);
+
+        Assert.That(result, Is.EqualTo("Ada-Ada-Ada"));
+    }
+
+    [Test]
+    public void Leaves_unknown_placeholder_untouched()
+    {
+        var result = "[UNKNOWN_TOKEN]".ReplacePlaceholders(new PersonModel());
+
+        Assert.That(result, Is.EqualTo("[UNKNOWN_TOKEN]"));
+    }
+
+    [Test]
+    public void Returns_template_unchanged_when_it_has_no_placeholders()
+    {
+        var result = "Hello world".ReplacePlaceholders(new PersonModel());
+
+        Assert.That(result, Is.EqualTo("Hello world"));
+    }
+
+    [Test]
+    public void Returns_empty_string_for_empty_template()
+    {
+        var result = string.Empty.ReplacePlaceholders(new PersonModel());
+
+        Assert.That(result, Is.Empty);
+    }
+
+    [Test]
+    public void Returns_template_unchanged_when_data_has_no_readable_properties()
+    {
+        var result = "[ANYTHING]".ReplacePlaceholders(new object());
+
+        Assert.That(result, Is.EqualTo("[ANYTHING]"));
+    }
+
+    [Test]
+    public void Matching_is_case_sensitive()
+    {
+        var result = "[name]|[Name]".ReplacePlaceholders(new PersonNameModel { Name = "v" });
+
+        Assert.That(result, Is.EqualTo("[name]|[Name]"));
+    }
+
+    [Test]
+    public void Placeholder_without_brackets_is_untouched()
+    {
+        var result = "NAME Receiver".ReplacePlaceholders(new PersonNameModel { Name = "v" });
+
+        Assert.That(result, Is.EqualTo("NAME Receiver"));
+    }
+
+    [Test]
+    public void Double_brackets_leave_the_outer_brackets()
+    {
+        var result = "[[NAME]]".ReplacePlaceholders(new PersonNameModel { Name = "v" });
+
+        Assert.That(result, Is.EqualTo("[v]"));
+    }
+
+    #endregion
+
+    #region Values
+
+    [Test]
+    public void Null_value_is_replaced_with_empty_string()
+    {
+        var result = "[NAME]".ReplacePlaceholders(new { Name = (string?)null });
+
+        Assert.That(result, Is.Empty);
+    }
+
+    [Test]
+    public void Custom_ToString_is_used()
+    {
+        var result = "[VALUE]".ReplacePlaceholders(new { Value = new CustomValue() });
+
+        Assert.That(result, Is.EqualTo("custom"));
+    }
+
+    [Test]
+    public void Primitive_values_use_ToString()
+    {
+        var result = "[COUNT]|[ENABLED]".ReplacePlaceholders(new { Count = 3, Enabled = true });
+
+        Assert.That(result, Is.EqualTo("3|True"));
+    }
+
+    [Test]
+    public void Regex_like_characters_are_inserted_literally()
+    {
+        var result = "[PATTERN]".ReplacePlaceholders(new { Pattern = @"$1 {0} \ $&" });
+
+        Assert.That(result, Is.EqualTo(@"$1 {0} \ $&"));
+    }
+
+    [Test]
+    public void Value_containing_its_own_placeholder_is_not_expanded_recursively()
+    {
+        var result = "[NAME]".ReplacePlaceholders(new EchoNameModel());
+
+        Assert.That(result, Is.EqualTo("[NAME]"));
+    }
+
+    [Test]
+    public void Unicode_value_is_preserved()
+    {
+        var result = "[NAME]".ReplacePlaceholders(new PersonNameModel { Name = "Z\u00fcrich \ud83d\ude00" });
+
+        Assert.That(result, Is.EqualTo("Z\u00fcrich \ud83d\ude00"));
+    }
+
+    #endregion
+
+    #region Property discovery
+
+    [Test]
+    public void Public_readable_property_is_replaced()
+    {
+        var result = "[SHOWN]".ReplacePlaceholders(new DiscoveryModel());
+
+        Assert.That(result, Is.EqualTo("shown"));
+    }
+
+    [Test]
+    public void Get_only_property_is_replaced()
+    {
+        var result = "[READ_ONLY]".ReplacePlaceholders(new DiscoveryModel());
+
+        Assert.That(result, Is.EqualTo("computed"));
+    }
+
+    [Test]
+    public void Static_private_write_only_and_indexer_properties_are_ignored()
+    {
+        const string template = "[HIDDEN]|[STATIC]|[WRITE_ONLY]|[ITEM]";
+
+        var result = template.ReplacePlaceholders(new DiscoveryModel());
+
+        Assert.That(result, Is.EqualTo(template));
+    }
+
+    [Test]
+    public void Inherited_public_property_is_replaced()
+    {
+        var result = "[ID]|[NAME]".ReplacePlaceholders(new DerivedModel());
+
+        Assert.That(result, Is.EqualTo("base|derived"));
+    }
+
+    [Test]
+    public void Record_properties_are_replaced()
+    {
+        var result = "[FIRST_NAME]/[AGE]".ReplacePlaceholders(new PersonRecord("Ada", 36));
+
+        Assert.That(result, Is.EqualTo("Ada/36"));
+    }
+
+    [Test]
+    public void Struct_data_is_supported()
+    {
+        var result = "[NAME]".ReplacePlaceholders(new StructModel { Name = "struct" });
+
+        Assert.That(result, Is.EqualTo("struct"));
+    }
+
+    [Test]
+    public void Anonymous_type_is_supported()
+    {
+        var data = new { Name = "anon", Age = 42 };
+
+        var result = "[NAME]|[AGE]".ReplacePlaceholders(data);
+
+        Assert.That(result, Is.EqualTo("anon|42"));
+    }
+
+    [Test]
+    public void Generic_type_is_supported_for_reference_type()
+    {
+        var result = "[VALUE]".ReplacePlaceholders(new Box<string> { Value = "boxed" });
+
+        Assert.That(result, Is.EqualTo("boxed"));
+    }
+
+    [Test]
+    public void Generic_type_is_supported_for_value_type()
+    {
+        var result = "[VALUE]".ReplacePlaceholders(new Box<int> { Value = 5 });
+
+        Assert.That(result, Is.EqualTo("5"));
+    }
+
+    #endregion
+
+    #region Cache and thread safety
+
+    [Test]
+    public void Cached_metadata_uses_values_of_current_instance()
+    {
+        var first = "[FIRST_NAME]".ReplacePlaceholders(new PersonModel { FirstName = "first" });
+        var second = "[FIRST_NAME]".ReplacePlaceholders(new PersonModel { FirstName = "second" });
+
+        Assert.That(new[] { first, second }, Is.EqualTo(new[] { "first", "second" }));
+    }
+
+    [Test]
+    public void Two_types_with_same_property_name_are_resolved_independently()
+    {
+        var a = "[NAME]".ReplacePlaceholders(new TypeA());
+        var b = "[NAME]".ReplacePlaceholders(new TypeB());
+
+        Assert.That(new[] { a, b }, Is.EqualTo(new[] { "a", "b" }));
+    }
+
+    [Test]
+    public void Concurrent_first_calls_are_thread_safe()
+    {
+        var failures = 0;
+
+        Parallel.For(0, 500, i =>
+        {
+            var expected = $"n{i}";
+            var actual = "[NAME]".ReplacePlaceholders(new ConcurrentModel { Name = expected });
+
+            if (actual != expected)
+                Interlocked.Increment(ref failures);
+        });
+
+        Assert.That(failures, Is.Zero);
+    }
+
+    #endregion
+
+    #region Real DTO
+
+    [Test]
+    public void Document_received_notification_is_fully_replaced()
+    {
+        var data = new DocumentReceivedNotification
+        {
+            DocumentTitle = "Vertrag",
+            NameReceiver = "Max",
+            NameSender = "Erika",
+            IsReadAndConfirm = true,
+            AdvancedSignature = false,
+            LinkToDocument = "https://x.io/a",
+            Message = "Bitte",
+            NamePortal = "Portal"
+        };
+
+        const string template =
+            "[NAME_RECEIVER]|[NAME_SENDER]|[SIGNATURE_TYPE]|[DOCUMENT_TITLE]|[MESSAGE]|[NAME_PORTAL]|[LINK_TO_DOCUMENT]|[LINK_TO_DOCUMENT_TEXT]";
+
+        var result = template.ReplacePlaceholders(data);
+
+        Assert.That(result, Is.EqualTo("Max|Erika|Signieren|Vertrag|Bitte|Portal|https://x.io/a|https://x.io/a"));
+    }
+
+    #endregion
+
+    #region Models
+
+    private sealed class PersonModel
+    {
+        public string FirstName { get; set; } = "v";
+        public string LastName { get; set; } = "v";
+    }
+
+    private sealed class PersonNameModel
+    {
+        public string Name { get; set; } = "v";
+    }
+
+    private sealed class IdModel
+    {
+        public string Id { get; set; } = "v";
+    }
+
+    private sealed class UpperIdModel
+    {
+        public string ID { get; set; } = "v";
+    }
+
+    private sealed class AcronymModel
+    {
+        public string URLValue { get; set; } = "v";
+        public string HTTPStatusCode { get; set; } = "v";
+        public string XMLHttpRequest { get; set; } = "v";
+        public string OTP { get; set; } = "v";
+    }
+
+    private sealed class DigitModel
+    {
+        public string Field1 { get; set; } = "v";
+        public string Value2Text { get; set; } = "v";
+        public string A1B2 { get; set; } = "v";
+        public string Name2 { get; set; } = "v";
+    }
+
+    private sealed class MyUrl2ValueModel
+    {
+        public string MyURL2Value { get; set; } = "v";
+    }
+
+    private sealed class SingleLetterModel
+    {
+        public string X { get; set; } = "v";
+    }
+
+    private sealed class LowerCaseModel
+    {
+        public string firstName { get; set; } = "v";
+    }
+
+    private sealed class LowerCaseInfoModel
+    {
+        public string info { get; set; } = "v";
+    }
+
+    private sealed class SnakeCaseModel
+    {
+        public string First_Name { get; set; } = "v";
+    }
+
+    private sealed class TfaModel
+    {
+        public string TFAExpiration { get; set; } = "v";
+    }
+
+    private sealed class CustomValue
+    {
+        public override string ToString() => "custom";
+    }
+
+    private sealed class EchoNameModel
+    {
+        public string Name { get; set; } = "[NAME]";
+    }
+
+    private sealed class DiscoveryModel
+    {
+        public static string Static { get; set; } = "static";
+
+        public string ReadOnly => "computed";
+
+        public string WriteOnly
+        {
+            set { }
+        }
+
+        public string this[int index] => "indexer";
+
+        public string Shown { get; set; } = "shown";
+
+        private string Hidden { get; set; } = "hidden";
+    }
+
+    private class BaseModel
+    {
+        public string Id { get; set; } = "base";
+    }
+
+    private sealed class DerivedModel : BaseModel
+    {
+        public string Name { get; set; } = "derived";
+    }
+
+    private sealed record PersonRecord(string FirstName, int Age);
+
+    private struct StructModel
+    {
+        public string Name { get; set; }
+    }
+
+    private sealed class Box<T>
+    {
+        public T Value { get; set; } = default!;
+    }
+
+    private sealed class TypeA
+    {
+        public string Name { get; set; } = "a";
+    }
+
+    private sealed class TypeB
+    {
+        public string Name { get; set; } = "b";
+    }
+
+    private sealed class ConcurrentModel
+    {
+        public string Name { get; set; } = string.Empty;
+    }
+
+    #endregion
+}