diff --git a/Examples/Program_ListenUpdates.cs b/Examples/Program_ListenUpdates.cs
index f500746..d4ebebb 100644
--- a/Examples/Program_ListenUpdates.cs
+++ b/Examples/Program_ListenUpdates.cs
@@ -26,7 +26,7 @@ namespace WTelegramClientTest
 			users[my.id] = my;
 			// note that on logging, Telegram may sends a bunch of updates/messages that happened in the past and were not acknowledged
 			Console.WriteLine($"We are logged-in as {my.username ?? my.first_name + " " + my.last_name} (id {my.id})");
-			var dialogsBase = await client.Messages_GetDialogs(default, 0, InputPeer.Empty, 0, 0);
+			var dialogsBase = await client.Messages_GetDialogs(default, 0, null, 0, 0);
 			if (dialogsBase is Messages_Dialogs dialogs)
 				while (dialogs.dialogs.Length != 0)
 				{
diff --git a/src/Encryption.cs b/src/Encryption.cs
index fc7161c..f3ce552 100644
--- a/src/Encryption.cs
+++ b/src/Encryption.cs
@@ -360,7 +360,7 @@ j4WcDuXc2CTHgH8gFTNhp/Y8/SpDOhvn9QIDAQAB
 			return output;
 		}
 
-		internal static InputCheckPasswordSRPBase Check2FA(Account_Password accountPassword, string password)
+		internal static InputCheckPasswordSRP Check2FA(Account_Password accountPassword, string password)
 		{
 			if (accountPassword.current_algo is not PasswordKdfAlgoSHA256SHA256PBKDF2HMACSHA512iter100000SHA256ModPow algo)
 				throw new ApplicationException("2FA authentication uses an unsupported algo: " + accountPassword.current_algo?.GetType().Name);
diff --git a/src/Generator.cs b/src/Generator.cs
index c5c0189..32b7183 100644
--- a/src/Generator.cs
+++ b/src/Generator.cs
@@ -113,6 +113,7 @@ namespace WTelegram
 				ctorToTypes[ctor.ID] = ctor.layer == 0 ? structName : $"Layer{ctor.layer}.{structName}";
 				var typeInfo = typeInfos.GetOrCreate(ctor.type);
 				if (ctor.ID == 0x5BB8E511) { ctorToTypes[ctor.ID] = structName = ctor.predicate = ctor.type = "_Message"; }
+				else if (ctor.ID == TL.Layer.NullCtor) { ctorToTypes[ctor.ID] += "=null"; typeInfo.Nullable = ctor; }
 				if (typeInfo.ReturnName == null) typeInfo.ReturnName = CSharpName(ctor.type);
 				typeInfo.Structs.Add(ctor);
 				if (structName == typeInfo.ReturnName) typeInfo.MainClass = ctor;
@@ -128,6 +129,15 @@ namespace WTelegram
 					}
 					continue;
 				}
+				if (typeInfo.Structs.All(ctor => ctor.@params.Length == 0))
+					typeInfo.AsEnum = true;
+				var nullable = typeInfo.Structs.Where(c => c.predicate.EndsWith("Empty") || c.predicate.EndsWith("Unknown")).ToList();
+				if (nullable.Count == 1 && nullable[0].@params.Length == 0 && !typeInfo.AsEnum)
+				{
+					typeInfo.Nullable = nullable[0];
+					typeInfo.Structs.Remove(typeInfo.Nullable);
+					ctorToTypes[typeInfo.Nullable.ID] += "=null";
+				}
 				if (typeInfo.MainClass == null)
 				{
 					List<Param> fakeCtorParams = new();
@@ -240,11 +250,13 @@ namespace WTelegram
 				if (needNewLine) { needNewLine = false; sw.WriteLine(); }
 				var parentClass = ctor == typeInfo.MainClass ? "ITLObject" : typeInfo.ReturnName;
 				var parms = ctor.@params;
-				if (ctorId == 0)
+				if (ctorId == 0) // abstract parent
 				{
 					if (currentJson != "TL.MTProto")
 						sw.WriteLine($"{tabIndent}///<summary>See <a href=\"https://core.telegram.org/type/{typeInfo.Structs[0].type}\"/></summary>");
-					if (typeInfo.Structs.All(ctor => ctor.@params.Length == 0))
+					if (typeInfo.Nullable != null)
+						sw.WriteLine($"{tabIndent}///<remarks>a <c>null</c> value means <a href=\"https://core.telegram.org/constructor/{typeInfo.Nullable.predicate}\">{typeInfo.Nullable.predicate}</a></remarks>");
+					if (typeInfo.AsEnum)
 					{
 						WriteTypeAsEnum(sw, typeInfo);
 						return;
@@ -290,6 +302,8 @@ namespace WTelegram
 					if (currentJson != "TL.MTProto")
 					{
 						sw.WriteLine($"{tabIndent}///<summary>See <a href=\"https://core.telegram.org/constructor/{ctor.predicate}\"/></summary>");
+						if (typeInfo.Nullable != null && ctor == typeInfo.MainClass)
+							sw.WriteLine($"{tabIndent}///<remarks>a <c>null</c> value means <a href=\"https://core.telegram.org/constructor/{typeInfo.Nullable.predicate}\">{typeInfo.Nullable.predicate}</a></remarks>");
 						sw.WriteLine($"{tabIndent}[TLDef(0x{ctor.ID:X8}{tldefReverse})]");
 					}
 					else
@@ -610,8 +624,10 @@ namespace WTelegram
 
 		void UpdateTable(string tableCs)
 		{
+			int tableId = 0;
 			var myTag = $"\t\t\t// from {currentJson}:";
 			var seen_ids = new HashSet<int>();
+			var seen_nullables = new HashSet<string>();
 			using (var sr = new StreamReader(tableCs))
 			using (var sw = new StreamWriter(tableCs + ".new", false, Encoding.UTF8))
 			{
@@ -624,9 +640,22 @@ namespace WTelegram
 						sw.WriteLine(line);
 					if (line == myTag)
 					{
-						foreach (var ctor in ctorToTypes)
-							if (seen_ids.Add(ctor.Key))
-								sw.WriteLine($"\t\t\t[0x{ctor.Key:X8}] = typeof({ctor.Value}),");
+						switch (++tableId)
+						{
+							case 1:
+								foreach (var ctor in ctorToTypes)
+									if (seen_ids.Add(ctor.Key))
+										if (ctor.Value.EndsWith("=null"))
+											sw.WriteLine($"\t\t\t[0x{ctor.Key:X8}] = null,//{ctor.Value[..^5]}");
+										else
+											sw.WriteLine($"\t\t\t[0x{ctor.Key:X8}] = typeof({ctor.Value}),");
+								break;
+							case 2:
+								foreach (var typeInfo in typeInfos.Values)
+									if (typeInfo.Nullable != null && seen_nullables.Add(typeInfo.ReturnName))
+										sw.WriteLine($"\t\t\t[typeof({typeInfo.ReturnName})]{new string(' ', 30 - typeInfo.ReturnName.Length)} = 0x{typeInfo.Nullable.ID:X8}, //{typeInfo.Nullable.predicate}");
+								break;
+						}
 						while ((line = sr.ReadLine()) != null)
 							if (line.StartsWith("\t\t\t// "))
 								break;
@@ -634,6 +663,8 @@ namespace WTelegram
 					}
 					else if (line.StartsWith("\t\t\t[0x"))
 						seen_ids.Add(int.Parse(line[6..14], System.Globalization.NumberStyles.HexNumber));
+					else if (line.StartsWith("\t\t\t[typeof("))
+						seen_nullables.Add(line[11..line.IndexOf(')')]);
 				}
 			}
 			File.Replace(tableCs + ".new", tableCs, null);
@@ -672,8 +703,10 @@ namespace WTelegram
 		{
 			public string ReturnName;
 			public Constructor MainClass;
+			public Constructor Nullable;
 			public List<Constructor> Structs = new();
 			internal int CommonFields; // n fields are common among all those classes
+			internal bool AsEnum;
 		}
 
 #pragma warning disable IDE1006 // Naming Styles
diff --git a/src/Helpers.TL.cs b/src/Helpers.TL.cs
index 7a412d1..a7fc6b2 100644
--- a/src/Helpers.TL.cs
+++ b/src/Helpers.TL.cs
@@ -6,14 +6,7 @@ using System.Web;
 
 namespace TL
 {
-	partial class InputChannel { public static InputPeerChannel Empty => new(); }
-	partial class InputDocument { public static InputDocumentEmpty Empty => new(); }
-	partial class InputPeer { public static InputPeerEmpty Empty => new(); }
 	partial class InputPeer { public static InputPeerSelf Self => new(); }
-	partial class InputPhoto { public static InputPhotoEmpty Empty => new(); }
-	partial class InputEncryptedFile { public static InputEncryptedFileEmpty Empty => new(); }
-	partial class InputStickerSet { public static InputStickerSetEmpty Empty => new(); }
-	partial class InputUser { public static InputUserEmpty Empty => new(); }
 	partial class InputUser { public static InputUserSelf Self => new(); }
 
 	partial class ChatBase
@@ -30,7 +23,7 @@ namespace TL
 		public override long ID => id;
 		public override string Title => null;
 		public override bool IsBanned(ChatBannedRights.Flags flags = 0) => true;
-		protected override InputPeer ToInputPeer() => InputPeer.Empty;
+		protected override InputPeer ToInputPeer() => null;
 	}
 	partial class Chat
 	{
@@ -75,8 +68,8 @@ namespace TL
 	{
 		public override long ID => id;
 		public override string DisplayName => null;
-		protected override InputPeer ToInputPeer() => InputPeer.Empty;
-		protected override InputUserBase ToInputUser() => InputUser.Empty;
+		protected override InputPeer ToInputPeer() => null;
+		protected override InputUserBase ToInputUser() => null;
 	}
 	partial class User
 	{
@@ -114,19 +107,19 @@ namespace TL
 	partial class PhotoBase
 	{
 		public abstract long ID { get; }
-		protected abstract InputPhotoBase ToInputPhoto();
-		public static implicit operator InputPhotoBase(PhotoBase photo) => photo.ToInputPhoto();
+		protected abstract InputPhoto ToInputPhoto();
+		public static implicit operator InputPhoto(PhotoBase photo) => photo.ToInputPhoto();
 	}
 	partial class PhotoEmpty
 	{
 		public override long ID => id;
-		protected override InputPhotoBase ToInputPhoto() => InputPhoto.Empty;
+		protected override InputPhoto ToInputPhoto() => null;
 	}
 	partial class Photo
 	{
 		public override long ID => id;
 
-		protected override InputPhotoBase ToInputPhoto() => new InputPhoto() { id = id, access_hash = access_hash, file_reference = file_reference };
+		protected override InputPhoto ToInputPhoto() => new() { id = id, access_hash = access_hash, file_reference = file_reference };
 		public InputPhotoFileLocation ToFileLocation() => ToFileLocation(LargestPhotoSize);
 		public InputPhotoFileLocation ToFileLocation(PhotoSizeBase photoSize) => new() { id = id, access_hash = access_hash, file_reference = file_reference, thumb_size = photoSize.Type };
 		public PhotoSizeBase LargestPhotoSize => sizes.Aggregate((agg, next) => (long)next.Width * next.Height > (long)agg.Width * agg.Height ? next : agg);
@@ -202,33 +195,24 @@ namespace TL
 	partial class DocumentBase
 	{
 		public abstract long ID { get; }
-		protected abstract InputDocumentBase ToInputDocument();
-		public static implicit operator InputDocumentBase(DocumentBase document) => document.ToInputDocument();
+		protected abstract InputDocument ToInputDocument();
+		public static implicit operator InputDocument(DocumentBase document) => document.ToInputDocument();
 	}
 	partial class DocumentEmpty
 	{
 		public override long ID => id;
-		protected override InputDocumentBase ToInputDocument() => InputDocument.Empty;
+		protected override InputDocument ToInputDocument() => null;
 	}
 	partial class Document
 	{
 		public override long ID => id;
-		protected override InputDocumentBase ToInputDocument() => new InputDocument() { id = id, access_hash = access_hash, file_reference = file_reference };
+		protected override InputDocument ToInputDocument() => new() { id = id, access_hash = access_hash, file_reference = file_reference };
 		public InputDocumentFileLocation ToFileLocation(PhotoSizeBase thumbSize = null) => new() { id = id, access_hash = access_hash, file_reference = file_reference, thumb_size = thumbSize?.Type };
 	}
 
-	partial class EncryptedFileBase
-	{
-		protected abstract InputEncryptedFileBase ToInputEncryptedFile();
-		public static implicit operator InputEncryptedFileBase(EncryptedFileBase file) => file.ToInputEncryptedFile();
-	}
-	partial class EncryptedFileEmpty
-	{
-		protected override InputEncryptedFileBase ToInputEncryptedFile() => InputEncryptedFile.Empty;
-	}
 	partial class EncryptedFile
 	{
-		protected override InputEncryptedFileBase ToInputEncryptedFile() => new InputEncryptedFile { id = id, access_hash = access_hash };
+		public static implicit operator InputEncryptedFile(EncryptedFile file) => file == null ? null : new InputEncryptedFile { id = file.id, access_hash = file.access_hash };
 		public InputEncryptedFileLocation ToFileLocation() => new() { id = id, access_hash = access_hash };
 	}
 
diff --git a/src/Session.cs b/src/Session.cs
index b177293..861f527 100644
--- a/src/Session.cs
+++ b/src/Session.cs
@@ -42,7 +42,7 @@ namespace WTelegram
 		private static readonly JsonSerializerOptions JsonOptions = new(Helpers.JsonOptions)
 		{
 			Converters = {
-				new Helpers.PolymorphicConverter<TL.UserProfilePhotoBase>(),
+				new Helpers.PolymorphicConverter<TL.UserProfilePhoto>(),
 				new Helpers.PolymorphicConverter<TL.UserStatus>()
 			}
 		};
diff --git a/src/TL.Schema.cs b/src/TL.Schema.cs
index fd5e6fd..8a9ec79 100644
--- a/src/TL.Schema.cs
+++ b/src/TL.Schema.cs
@@ -29,14 +29,13 @@ namespace TL
 	}
 
 	///<summary>See <a href="https://core.telegram.org/constructor/null"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/null">null</a></remarks>
 	[TLDef(0x56730BCC)]
 	public partial class Null : ITLObject { }
 
 	///<summary>See <a href="https://core.telegram.org/type/InputPeer"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputPeerEmpty">inputPeerEmpty</a></remarks>
 	public abstract partial class InputPeer : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputPeerEmpty"/></summary>
-	[TLDef(0x7F3B18EA)]
-	public partial class InputPeerEmpty : InputPeer { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputPeerSelf"/></summary>
 	[TLDef(0x7DA07EC9)]
 	public partial class InputPeerSelf : InputPeer { }
@@ -75,10 +74,8 @@ namespace TL
 	}
 
 	///<summary>See <a href="https://core.telegram.org/type/InputUser"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputUserEmpty">inputUserEmpty</a></remarks>
 	public abstract partial class InputUserBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputUserEmpty"/></summary>
-	[TLDef(0xB98886CF)]
-	public partial class InputUserEmpty : InputUserBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputUserSelf"/></summary>
 	[TLDef(0xF7C1B13F)]
 	public partial class InputUserSelf : InputUserBase { }
@@ -131,10 +128,8 @@ namespace TL
 	}
 
 	///<summary>See <a href="https://core.telegram.org/type/InputMedia"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputMediaEmpty">inputMediaEmpty</a></remarks>
 	public abstract partial class InputMedia : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputMediaEmpty"/></summary>
-	[TLDef(0x9664F57F)]
-	public partial class InputMediaEmpty : InputMedia { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputMediaUploadedPhoto"/></summary>
 	[TLDef(0x1E287D04)]
 	public partial class InputMediaUploadedPhoto : InputMedia
@@ -142,7 +137,7 @@ namespace TL
 		[Flags] public enum Flags { has_stickers = 0x1, has_ttl_seconds = 0x2 }
 		public Flags flags;
 		public InputFileBase file;
-		[IfFlag(0)] public InputDocumentBase[] stickers;
+		[IfFlag(0)] public InputDocument[] stickers;
 		[IfFlag(1)] public int ttl_seconds;
 	}
 	///<summary>See <a href="https://core.telegram.org/constructor/inputMediaPhoto"/></summary>
@@ -151,12 +146,12 @@ namespace TL
 	{
 		[Flags] public enum Flags { has_ttl_seconds = 0x1 }
 		public Flags flags;
-		public InputPhotoBase id;
+		public InputPhoto id;
 		[IfFlag(0)] public int ttl_seconds;
 	}
 	///<summary>See <a href="https://core.telegram.org/constructor/inputMediaGeoPoint"/></summary>
 	[TLDef(0xF9C44144)]
-	public partial class InputMediaGeoPoint : InputMedia { public InputGeoPointBase geo_point; }
+	public partial class InputMediaGeoPoint : InputMedia { public InputGeoPoint geo_point; }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputMediaContact"/></summary>
 	[TLDef(0xF8AB7DFB)]
 	public partial class InputMediaContact : InputMedia
@@ -176,7 +171,7 @@ namespace TL
 		[IfFlag(2)] public InputFileBase thumb;
 		public string mime_type;
 		public DocumentAttribute[] attributes;
-		[IfFlag(0)] public InputDocumentBase[] stickers;
+		[IfFlag(0)] public InputDocument[] stickers;
 		[IfFlag(1)] public int ttl_seconds;
 	}
 	///<summary>See <a href="https://core.telegram.org/constructor/inputMediaDocument"/></summary>
@@ -185,7 +180,7 @@ namespace TL
 	{
 		[Flags] public enum Flags { has_ttl_seconds = 0x1, has_query = 0x2 }
 		public Flags flags;
-		public InputDocumentBase id;
+		public InputDocument id;
 		[IfFlag(0)] public int ttl_seconds;
 		[IfFlag(1)] public string query;
 	}
@@ -193,7 +188,7 @@ namespace TL
 	[TLDef(0xC13D1C11)]
 	public partial class InputMediaVenue : InputMedia
 	{
-		public InputGeoPointBase geo_point;
+		public InputGeoPoint geo_point;
 		public string title;
 		public string address;
 		public string provider;
@@ -242,7 +237,7 @@ namespace TL
 	{
 		[Flags] public enum Flags { stopped = 0x1, has_period = 0x2, has_heading = 0x4, has_proximity_notification_radius = 0x8 }
 		public Flags flags;
-		public InputGeoPointBase geo_point;
+		public InputGeoPoint geo_point;
 		[IfFlag(2)] public int heading;
 		[IfFlag(1)] public int period;
 		[IfFlag(3)] public int proximity_notification_radius;
@@ -263,10 +258,8 @@ namespace TL
 	public partial class InputMediaDice : InputMedia { public string emoticon; }
 
 	///<summary>See <a href="https://core.telegram.org/type/InputChatPhoto"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputChatPhotoEmpty">inputChatPhotoEmpty</a></remarks>
 	public abstract partial class InputChatPhotoBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputChatPhotoEmpty"/></summary>
-	[TLDef(0x1CA48F57)]
-	public partial class InputChatPhotoEmpty : InputChatPhotoBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputChatUploadedPhoto"/></summary>
 	[TLDef(0xC642724E)]
 	public partial class InputChatUploadedPhoto : InputChatPhotoBase
@@ -279,16 +272,12 @@ namespace TL
 	}
 	///<summary>See <a href="https://core.telegram.org/constructor/inputChatPhoto"/></summary>
 	[TLDef(0x8953AD37)]
-	public partial class InputChatPhoto : InputChatPhotoBase { public InputPhotoBase id; }
+	public partial class InputChatPhoto : InputChatPhotoBase { public InputPhoto id; }
 
-	///<summary>See <a href="https://core.telegram.org/type/InputGeoPoint"/></summary>
-	public abstract partial class InputGeoPointBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputGeoPointEmpty"/></summary>
-	[TLDef(0xE4C123D6)]
-	public partial class InputGeoPointEmpty : InputGeoPointBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputGeoPoint"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputGeoPointEmpty">inputGeoPointEmpty</a></remarks>
 	[TLDef(0x48222FAF)]
-	public partial class InputGeoPoint : InputGeoPointBase
+	public partial class InputGeoPoint : ITLObject
 	{
 		[Flags] public enum Flags { has_accuracy_radius = 0x1 }
 		public Flags flags;
@@ -297,14 +286,10 @@ namespace TL
 		[IfFlag(0)] public int accuracy_radius;
 	}
 
-	///<summary>See <a href="https://core.telegram.org/type/InputPhoto"/></summary>
-	public abstract partial class InputPhotoBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputPhotoEmpty"/></summary>
-	[TLDef(0x1CD7BF0D)]
-	public partial class InputPhotoEmpty : InputPhotoBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputPhoto"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputPhotoEmpty">inputPhotoEmpty</a></remarks>
 	[TLDef(0x3BB3B94A)]
-	public partial class InputPhoto : InputPhotoBase
+	public partial class InputPhoto : ITLObject
 	{
 		public long id;
 		public long access_hash;
@@ -455,7 +440,7 @@ namespace TL
 		[IfFlag(2)] public string last_name;
 		[IfFlag(3)] public string username;
 		[IfFlag(4)] public string phone;
-		[IfFlag(5)] public UserProfilePhotoBase photo;
+		[IfFlag(5)] public UserProfilePhoto photo;
 		[IfFlag(6)] public UserStatus status;
 		[IfFlag(14)] public int bot_info_version;
 		[IfFlag(18)] public RestrictionReason[] restriction_reason;
@@ -463,14 +448,10 @@ namespace TL
 		[IfFlag(22)] public string lang_code;
 	}
 
-	///<summary>See <a href="https://core.telegram.org/type/UserProfilePhoto"/></summary>
-	public abstract partial class UserProfilePhotoBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/userProfilePhotoEmpty"/></summary>
-	[TLDef(0x4F11BAE1)]
-	public partial class UserProfilePhotoEmpty : UserProfilePhotoBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/userProfilePhoto"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/userProfilePhotoEmpty">userProfilePhotoEmpty</a></remarks>
 	[TLDef(0x82D1F706)]
-	public partial class UserProfilePhoto : UserProfilePhotoBase
+	public partial class UserProfilePhoto : ITLObject
 	{
 		[Flags] public enum Flags { has_video = 0x1, has_stripped_thumb = 0x2 }
 		public Flags flags;
@@ -480,10 +461,8 @@ namespace TL
 	}
 
 	///<summary>See <a href="https://core.telegram.org/type/UserStatus"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/userStatusEmpty">userStatusEmpty</a></remarks>
 	public abstract partial class UserStatus : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/userStatusEmpty"/></summary>
-	[TLDef(0x09D05049)]
-	public partial class UserStatusEmpty : UserStatus { }
 	///<summary>See <a href="https://core.telegram.org/constructor/userStatusOnline"/></summary>
 	[TLDef(0xEDB93949)]
 	public partial class UserStatusOnline : UserStatus { public DateTime expires; }
@@ -514,7 +493,7 @@ namespace TL
 		public Flags flags;
 		public long id;
 		public string title;
-		public ChatPhotoBase photo;
+		public ChatPhoto photo;
 		public int participants_count;
 		public DateTime date;
 		public int version;
@@ -543,7 +522,7 @@ namespace TL
 		[IfFlag(13)] public long access_hash;
 		public string title;
 		[IfFlag(6)] public string username;
-		public ChatPhotoBase photo;
+		public ChatPhoto photo;
 		public DateTime date;
 		[IfFlag(9)] public RestrictionReason[] restriction_reason;
 		[IfFlag(14)] public ChatAdminRights admin_rights;
@@ -621,7 +600,7 @@ namespace TL
 		[IfFlag(9)] public int available_min_id;
 		[IfFlag(11)] public int folder_id;
 		[IfFlag(14)] public long linked_chat_id;
-		[IfFlag(15)] public ChannelLocationBase location;
+		[IfFlag(15)] public ChannelLocation location;
 		[IfFlag(17)] public int slowmode_seconds;
 		[IfFlag(18)] public DateTime slowmode_next_send_date;
 		[IfFlag(12)] public int stats_dc;
@@ -670,14 +649,10 @@ namespace TL
 		public int version;
 	}
 
-	///<summary>See <a href="https://core.telegram.org/type/ChatPhoto"/></summary>
-	public abstract partial class ChatPhotoBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/chatPhotoEmpty"/></summary>
-	[TLDef(0x37C1011C)]
-	public partial class ChatPhotoEmpty : ChatPhotoBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/chatPhoto"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/chatPhotoEmpty">chatPhotoEmpty</a></remarks>
 	[TLDef(0x1C6E1C11)]
-	public partial class ChatPhoto : ChatPhotoBase
+	public partial class ChatPhoto : ITLObject
 	{
 		[Flags] public enum Flags { has_video = 0x1, has_stripped_thumb = 0x2 }
 		public Flags flags;
@@ -744,10 +719,8 @@ namespace TL
 	}
 
 	///<summary>See <a href="https://core.telegram.org/type/MessageMedia"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/messageMediaEmpty">messageMediaEmpty</a></remarks>
 	public abstract partial class MessageMedia : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/messageMediaEmpty"/></summary>
-	[TLDef(0x3DED6320)]
-	public partial class MessageMediaEmpty : MessageMedia { }
 	///<summary>See <a href="https://core.telegram.org/constructor/messageMediaPhoto"/></summary>
 	[TLDef(0x695150D7)]
 	public partial class MessageMediaPhoto : MessageMedia
@@ -759,7 +732,7 @@ namespace TL
 	}
 	///<summary>See <a href="https://core.telegram.org/constructor/messageMediaGeo"/></summary>
 	[TLDef(0x56E0D474)]
-	public partial class MessageMediaGeo : MessageMedia { public GeoPointBase geo; }
+	public partial class MessageMediaGeo : MessageMedia { public GeoPoint geo; }
 	///<summary>See <a href="https://core.telegram.org/constructor/messageMediaContact"/></summary>
 	[TLDef(0x70322949)]
 	public partial class MessageMediaContact : MessageMedia
@@ -789,7 +762,7 @@ namespace TL
 	[TLDef(0x2EC0533F)]
 	public partial class MessageMediaVenue : MessageMedia
 	{
-		public GeoPointBase geo;
+		public GeoPoint geo;
 		public string title;
 		public string address;
 		public string provider;
@@ -819,7 +792,7 @@ namespace TL
 	{
 		[Flags] public enum Flags { has_heading = 0x1, has_proximity_notification_radius = 0x2 }
 		public Flags flags;
-		public GeoPointBase geo;
+		public GeoPoint geo;
 		[IfFlag(0)] public int heading;
 		public int period;
 		[IfFlag(1)] public int proximity_notification_radius;
@@ -840,10 +813,8 @@ namespace TL
 	}
 
 	///<summary>See <a href="https://core.telegram.org/type/MessageAction"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/messageActionEmpty">messageActionEmpty</a></remarks>
 	public abstract partial class MessageAction : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/messageActionEmpty"/></summary>
-	[TLDef(0xB6AEF7B0)]
-	public partial class MessageActionEmpty : MessageAction { }
 	///<summary>See <a href="https://core.telegram.org/constructor/messageActionChatCreate"/></summary>
 	[TLDef(0xBD47CBAD)]
 	public partial class MessageActionChatCreate : MessageAction
@@ -1086,14 +1057,10 @@ namespace TL
 		public byte[] bytes;
 	}
 
-	///<summary>See <a href="https://core.telegram.org/type/GeoPoint"/></summary>
-	public abstract partial class GeoPointBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/geoPointEmpty"/></summary>
-	[TLDef(0x1117DD5F)]
-	public partial class GeoPointEmpty : GeoPointBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/geoPoint"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/geoPointEmpty">geoPointEmpty</a></remarks>
 	[TLDef(0xB2A2F663)]
-	public partial class GeoPoint : GeoPointBase
+	public partial class GeoPoint : ITLObject
 	{
 		[Flags] public enum Flags { has_accuracy_radius = 0x1 }
 		public Flags flags;
@@ -1400,10 +1367,8 @@ namespace TL
 	}
 
 	///<summary>See <a href="https://core.telegram.org/type/MessagesFilter"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputMessagesFilterEmpty">inputMessagesFilterEmpty</a></remarks>
 	public abstract partial class MessagesFilter : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputMessagesFilterEmpty"/></summary>
-	[TLDef(0x57E2F66C)]
-	public partial class InputMessagesFilterEmpty : MessagesFilter { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputMessagesFilterPhotos"/></summary>
 	[TLDef(0x9609A51C)]
 	public partial class InputMessagesFilterPhotos : MessagesFilter { }
@@ -1521,7 +1486,7 @@ namespace TL
 	{
 		public long user_id;
 		public DateTime date;
-		public UserProfilePhotoBase photo;
+		public UserProfilePhoto photo;
 		public bool previous;
 	}
 	///<summary>See <a href="https://core.telegram.org/constructor/updateNewEncryptedMessage"/></summary>
@@ -1710,7 +1675,7 @@ namespace TL
 		public long query_id;
 		public long user_id;
 		public string query;
-		[IfFlag(0)] public GeoPointBase geo;
+		[IfFlag(0)] public GeoPoint geo;
 		[IfFlag(1)] public InlineQueryPeerType peer_type;
 		public string offset;
 	}
@@ -1722,7 +1687,7 @@ namespace TL
 		public Flags flags;
 		public long user_id;
 		public string query;
-		[IfFlag(0)] public GeoPointBase geo;
+		[IfFlag(0)] public GeoPoint geo;
 		public string id;
 		[IfFlag(1)] public InputBotInlineMessageIDBase msg_id;
 	}
@@ -2445,14 +2410,10 @@ namespace TL
 		public long access_hash;
 	}
 
-	///<summary>See <a href="https://core.telegram.org/type/EncryptedFile"/></summary>
-	public abstract partial class EncryptedFileBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/encryptedFileEmpty"/></summary>
-	[TLDef(0xC21F497E)]
-	public partial class EncryptedFileEmpty : EncryptedFileBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/encryptedFile"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/encryptedFileEmpty">encryptedFileEmpty</a></remarks>
 	[TLDef(0x4A70994C)]
-	public partial class EncryptedFile : EncryptedFileBase
+	public partial class EncryptedFile : ITLObject
 	{
 		public long id;
 		public long access_hash;
@@ -2462,10 +2423,8 @@ namespace TL
 	}
 
 	///<summary>See <a href="https://core.telegram.org/type/InputEncryptedFile"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputEncryptedFileEmpty">inputEncryptedFileEmpty</a></remarks>
 	public abstract partial class InputEncryptedFileBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputEncryptedFileEmpty"/></summary>
-	[TLDef(0x1837C364)]
-	public partial class InputEncryptedFileEmpty : InputEncryptedFileBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputEncryptedFileUploaded"/></summary>
 	[TLDef(0x64BD0306)]
 	public partial class InputEncryptedFileUploaded : InputEncryptedFileBase
@@ -2501,7 +2460,7 @@ namespace TL
 		public int chat_id;
 		public DateTime date;
 		public byte[] bytes;
-		public EncryptedFileBase file;
+		public EncryptedFile file;
 	}
 	///<summary>See <a href="https://core.telegram.org/constructor/encryptedMessageService"/></summary>
 	[TLDef(0x23734B06)]
@@ -2533,16 +2492,12 @@ namespace TL
 	public partial class Messages_SentEncryptedMessage : ITLObject { public DateTime date; }
 	///<summary>See <a href="https://core.telegram.org/constructor/messages.sentEncryptedFile"/></summary>
 	[TLDef(0x9493FF32)]
-	public partial class Messages_SentEncryptedFile : Messages_SentEncryptedMessage { public EncryptedFileBase file; }
+	public partial class Messages_SentEncryptedFile : Messages_SentEncryptedMessage { public EncryptedFile file; }
 
-	///<summary>See <a href="https://core.telegram.org/type/InputDocument"/></summary>
-	public abstract partial class InputDocumentBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputDocumentEmpty"/></summary>
-	[TLDef(0x72F0EAAE)]
-	public partial class InputDocumentEmpty : InputDocumentBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputDocument"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputDocumentEmpty">inputDocumentEmpty</a></remarks>
 	[TLDef(0x1ABFB575)]
-	public partial class InputDocument : InputDocumentBase
+	public partial class InputDocument : ITLObject
 	{
 		public long id;
 		public long access_hash;
@@ -3035,10 +2990,8 @@ namespace TL
 	}
 
 	///<summary>See <a href="https://core.telegram.org/type/InputStickerSet"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputStickerSetEmpty">inputStickerSetEmpty</a></remarks>
 	public abstract partial class InputStickerSet : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputStickerSetEmpty"/></summary>
-	[TLDef(0xFFB62B95)]
-	public partial class InputStickerSetEmpty : InputStickerSet { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputStickerSetID"/></summary>
 	[TLDef(0x9DE7A269)]
 	public partial class InputStickerSetID : InputStickerSet
@@ -3269,10 +3222,8 @@ namespace TL
 	public partial class MessageEntityBankCard : MessageEntity { }
 
 	///<summary>See <a href="https://core.telegram.org/type/InputChannel"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputChannelEmpty">inputChannelEmpty</a></remarks>
 	public abstract partial class InputChannelBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputChannelEmpty"/></summary>
-	[TLDef(0xEE8C1E86)]
-	public partial class InputChannelEmpty : InputChannelBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputChannel"/></summary>
 	[TLDef(0xF35AEC28)]
 	public partial class InputChannel : InputChannelBase
@@ -3343,14 +3294,10 @@ namespace TL
 		public UserBase[] users;
 	}
 
-	///<summary>See <a href="https://core.telegram.org/type/ChannelMessagesFilter"/></summary>
-	public abstract partial class ChannelMessagesFilterBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/channelMessagesFilterEmpty"/></summary>
-	[TLDef(0x94D42EE7)]
-	public partial class ChannelMessagesFilterEmpty : ChannelMessagesFilterBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/channelMessagesFilter"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/channelMessagesFilterEmpty">channelMessagesFilterEmpty</a></remarks>
 	[TLDef(0xCD77D957)]
-	public partial class ChannelMessagesFilter : ChannelMessagesFilterBase
+	public partial class ChannelMessagesFilter : ITLObject
 	{
 		[Flags] public enum Flags { exclude_new_messages = 0x2 }
 		public Flags flags;
@@ -3520,7 +3467,7 @@ namespace TL
 	{
 		[Flags] public enum Flags { has_heading = 0x1, has_period = 0x2, has_reply_markup = 0x4, 
 			has_proximity_notification_radius = 0x8 }
-		public InputGeoPointBase geo_point;
+		public InputGeoPoint geo_point;
 		[IfFlag(0)] public int heading;
 		[IfFlag(1)] public int period;
 		[IfFlag(3)] public int proximity_notification_radius;
@@ -3531,7 +3478,7 @@ namespace TL
 	public partial class InputBotInlineMessageMediaVenue : InputBotInlineMessage
 	{
 		[Flags] public enum Flags { has_reply_markup = 0x4 }
-		public InputGeoPointBase geo_point;
+		public InputGeoPoint geo_point;
 		public string title;
 		public string address;
 		public string provider;
@@ -3595,7 +3542,7 @@ namespace TL
 	{
 		public string id;
 		public string type;
-		public InputPhotoBase photo;
+		public InputPhoto photo;
 		public InputBotInlineMessage send_message;
 	}
 	///<summary>See <a href="https://core.telegram.org/constructor/inputBotInlineResultDocument"/></summary>
@@ -3608,7 +3555,7 @@ namespace TL
 		public string type;
 		[IfFlag(1)] public string title;
 		[IfFlag(2)] public string description;
-		public InputDocumentBase document;
+		public InputDocument document;
 		public InputBotInlineMessage send_message;
 	}
 	///<summary>See <a href="https://core.telegram.org/constructor/inputBotInlineResultGame"/></summary>
@@ -3646,7 +3593,7 @@ namespace TL
 	{
 		[Flags] public enum Flags { has_heading = 0x1, has_period = 0x2, has_reply_markup = 0x4, 
 			has_proximity_notification_radius = 0x8 }
-		public GeoPointBase geo;
+		public GeoPoint geo;
 		[IfFlag(0)] public int heading;
 		[IfFlag(1)] public int period;
 		[IfFlag(3)] public int proximity_notification_radius;
@@ -3657,7 +3604,7 @@ namespace TL
 	public partial class BotInlineMessageMediaVenue : BotInlineMessage
 	{
 		[Flags] public enum Flags { has_reply_markup = 0x4 }
-		public GeoPointBase geo;
+		public GeoPoint geo;
 		public string title;
 		public string address;
 		public string provider;
@@ -3999,10 +3946,10 @@ namespace TL
 	public abstract partial class InputStickeredMedia : ITLObject { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputStickeredMediaPhoto"/></summary>
 	[TLDef(0x4A992157)]
-	public partial class InputStickeredMediaPhoto : InputStickeredMedia { public InputPhotoBase id; }
+	public partial class InputStickeredMediaPhoto : InputStickeredMedia { public InputPhoto id; }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputStickeredMediaDocument"/></summary>
 	[TLDef(0x0438865B)]
-	public partial class InputStickeredMediaDocument : InputStickeredMedia { public InputDocumentBase id; }
+	public partial class InputStickeredMediaDocument : InputStickeredMedia { public InputDocument id; }
 
 	///<summary>See <a href="https://core.telegram.org/constructor/game"/></summary>
 	[TLDef(0xBDF9653B)]
@@ -4054,10 +4001,8 @@ namespace TL
 	}
 
 	///<summary>See <a href="https://core.telegram.org/type/RichText"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/textEmpty">textEmpty</a></remarks>
 	public abstract partial class RichText : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/textEmpty"/></summary>
-	[TLDef(0xDC3D824F)]
-	public partial class TextEmpty : RichText { }
 	///<summary>See <a href="https://core.telegram.org/constructor/textPlain"/></summary>
 	[TLDef(0x744694E0)]
 	public partial class TextPlain : RichText { public string text; }
@@ -4294,7 +4239,7 @@ namespace TL
 	[TLDef(0xA44F3EF6)]
 	public partial class PageBlockMap : PageBlock
 	{
-		public GeoPointBase geo;
+		public GeoPoint geo;
 		public int zoom;
 		public int w;
 		public int h;
@@ -4427,7 +4372,7 @@ namespace TL
 	[TLDef(0x9F2221C9)]
 	public partial class InputWebFileGeoPointLocation : InputWebFileLocationBase
 	{
-		public InputGeoPointBase geo_point;
+		public InputGeoPoint geo_point;
 		public long access_hash;
 		public int w;
 		public int h;
@@ -4562,7 +4507,7 @@ namespace TL
 	{
 		[Flags] public enum Flags { has_mask_coords = 0x1 }
 		public Flags flags;
-		public InputDocumentBase document;
+		public InputDocument document;
 		public string emoji;
 		[IfFlag(0)] public MaskCoords mask_coords;
 	}
@@ -4873,8 +4818,8 @@ namespace TL
 	[TLDef(0x0E6B76AE)]
 	public partial class ChannelAdminLogEventActionChangeLocation : ChannelAdminLogEventAction
 	{
-		public ChannelLocationBase prev_value;
-		public ChannelLocationBase new_value;
+		public ChannelLocation prev_value;
+		public ChannelLocation new_value;
 	}
 	///<summary>See <a href="https://core.telegram.org/constructor/channelAdminLogEventActionToggleSlowMode"/></summary>
 	[TLDef(0x53909779)]
@@ -5145,14 +5090,10 @@ namespace TL
 		public long access_hash;
 	}
 
-	///<summary>See <a href="https://core.telegram.org/type/SecureFile"/></summary>
-	public abstract partial class SecureFileBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/secureFileEmpty"/></summary>
-	[TLDef(0x64199744)]
-	public partial class SecureFileEmpty : SecureFileBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/secureFile"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/secureFileEmpty">secureFileEmpty</a></remarks>
 	[TLDef(0xE0277A62)]
-	public partial class SecureFile : SecureFileBase
+	public partial class SecureFile : ITLObject
 	{
 		public long id;
 		public long access_hash;
@@ -5221,11 +5162,11 @@ namespace TL
 		public Flags flags;
 		public SecureValueType type;
 		[IfFlag(0)] public SecureData data;
-		[IfFlag(1)] public SecureFileBase front_side;
-		[IfFlag(2)] public SecureFileBase reverse_side;
-		[IfFlag(3)] public SecureFileBase selfie;
-		[IfFlag(6)] public SecureFileBase[] translation;
-		[IfFlag(4)] public SecureFileBase[] files;
+		[IfFlag(1)] public SecureFile front_side;
+		[IfFlag(2)] public SecureFile reverse_side;
+		[IfFlag(3)] public SecureFile selfie;
+		[IfFlag(6)] public SecureFile[] translation;
+		[IfFlag(4)] public SecureFile[] files;
 		[IfFlag(5)] public SecurePlainData plain_data;
 		public byte[] hash;
 	}
@@ -5351,14 +5292,10 @@ namespace TL
 		public int length;
 	}
 
-	///<summary>See <a href="https://core.telegram.org/type/help.DeepLinkInfo"/></summary>
-	public abstract partial class Help_DeepLinkInfoBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/help.deepLinkInfoEmpty"/></summary>
-	[TLDef(0x66AFA166)]
-	public partial class Help_DeepLinkInfoEmpty : Help_DeepLinkInfoBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/help.deepLinkInfo"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/help.deepLinkInfoEmpty">help.deepLinkInfoEmpty</a></remarks>
 	[TLDef(0x6A4EE832)]
-	public partial class Help_DeepLinkInfo : Help_DeepLinkInfoBase
+	public partial class Help_DeepLinkInfo : ITLObject
 	{
 		[Flags] public enum Flags { update_app = 0x1, has_entities = 0x2 }
 		public Flags flags;
@@ -5383,10 +5320,8 @@ namespace TL
 	public partial class Account_Takeout : ITLObject { public long id; }
 
 	///<summary>See <a href="https://core.telegram.org/type/PasswordKdfAlgo"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/passwordKdfAlgoUnknown">passwordKdfAlgoUnknown</a></remarks>
 	public abstract partial class PasswordKdfAlgo : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/passwordKdfAlgoUnknown"/></summary>
-	[TLDef(0xD45AB096)]
-	public partial class PasswordKdfAlgoUnknown : PasswordKdfAlgo { }
 	///<summary>See <a href="https://core.telegram.org/constructor/passwordKdfAlgoSHA256SHA256PBKDF2HMACSHA512iter100000SHA256ModPow"/></summary>
 	[TLDef(0x3A912D4A)]
 	public partial class PasswordKdfAlgoSHA256SHA256PBKDF2HMACSHA512iter100000SHA256ModPow : PasswordKdfAlgo
@@ -5398,16 +5333,14 @@ namespace TL
 	}
 
 	///<summary>See <a href="https://core.telegram.org/type/SecurePasswordKdfAlgo"/></summary>
-	public abstract partial class SecurePasswordKdfAlgo : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/securePasswordKdfAlgoUnknown"/></summary>
-	[TLDef(0x004A8537)]
-	public partial class SecurePasswordKdfAlgoUnknown : SecurePasswordKdfAlgo { }
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/securePasswordKdfAlgoUnknown">securePasswordKdfAlgoUnknown</a></remarks>
+	public abstract partial class SecurePasswordKdfAlgo : ITLObject { public byte[] salt; }
 	///<summary>See <a href="https://core.telegram.org/constructor/securePasswordKdfAlgoPBKDF2HMACSHA512iter100000"/></summary>
 	[TLDef(0xBBF2DDA0)]
-	public partial class SecurePasswordKdfAlgoPBKDF2HMACSHA512iter100000 : SecurePasswordKdfAlgo { public byte[] salt; }
+	public partial class SecurePasswordKdfAlgoPBKDF2HMACSHA512iter100000 : SecurePasswordKdfAlgo { }
 	///<summary>See <a href="https://core.telegram.org/constructor/securePasswordKdfAlgoSHA512"/></summary>
 	[TLDef(0x86471D92)]
-	public partial class SecurePasswordKdfAlgoSHA512 : SecurePasswordKdfAlgo { public byte[] salt; }
+	public partial class SecurePasswordKdfAlgoSHA512 : SecurePasswordKdfAlgo { }
 
 	///<summary>See <a href="https://core.telegram.org/constructor/secureSecretSettings"/></summary>
 	[TLDef(0x1527BCAC)]
@@ -5418,14 +5351,10 @@ namespace TL
 		public long secure_secret_id;
 	}
 
-	///<summary>See <a href="https://core.telegram.org/type/InputCheckPasswordSRP"/></summary>
-	public abstract partial class InputCheckPasswordSRPBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/inputCheckPasswordEmpty"/></summary>
-	[TLDef(0x9880F658)]
-	public partial class InputCheckPasswordEmpty : InputCheckPasswordSRPBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/inputCheckPasswordSRP"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/inputCheckPasswordEmpty">inputCheckPasswordEmpty</a></remarks>
 	[TLDef(0xD27FF082)]
-	public partial class InputCheckPasswordSRP : InputCheckPasswordSRPBase
+	public partial class InputCheckPasswordSRP : ITLObject
 	{
 		public long srp_id;
 		public byte[] A;
@@ -5575,14 +5504,10 @@ namespace TL
 	[TLDef(0x8C05F1C9)]
 	public partial class Help_SupportName : ITLObject { public string name; }
 
-	///<summary>See <a href="https://core.telegram.org/type/help.UserInfo"/></summary>
-	public abstract partial class Help_UserInfoBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/help.userInfoEmpty"/></summary>
-	[TLDef(0xF3AE2EED)]
-	public partial class Help_UserInfoEmpty : Help_UserInfoBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/help.userInfo"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/help.userInfoEmpty">help.userInfoEmpty</a></remarks>
 	[TLDef(0x01EB3758)]
-	public partial class Help_UserInfo : Help_UserInfoBase
+	public partial class Help_UserInfo : ITLObject
 	{
 		public string message;
 		public MessageEntity[] entities;
@@ -5775,7 +5700,7 @@ namespace TL
 		public Flags flags;
 		public int id;
 		public string title;
-		[IfFlag(3)] public ChatPhotoBase photo;
+		[IfFlag(3)] public ChatPhoto photo;
 	}
 
 	///<summary>See <a href="https://core.telegram.org/constructor/inputFolderPeer"/></summary>
@@ -5822,16 +5747,12 @@ namespace TL
 	[TLDef(0xA9D6DB1F)]
 	public partial class UrlAuthResultDefault : UrlAuthResult { }
 
-	///<summary>See <a href="https://core.telegram.org/type/ChannelLocation"/></summary>
-	public abstract partial class ChannelLocationBase : ITLObject { }
-	///<summary>See <a href="https://core.telegram.org/constructor/channelLocationEmpty"/></summary>
-	[TLDef(0xBFB5AD8B)]
-	public partial class ChannelLocationEmpty : ChannelLocationBase { }
 	///<summary>See <a href="https://core.telegram.org/constructor/channelLocation"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/channelLocationEmpty">channelLocationEmpty</a></remarks>
 	[TLDef(0x209B82DB)]
-	public partial class ChannelLocation : ChannelLocationBase
+	public partial class ChannelLocation : ITLObject
 	{
-		public GeoPointBase geo_point;
+		public GeoPoint geo_point;
 		public string address;
 	}
 
@@ -6819,7 +6740,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/auth.checkPassword"/></summary>
-		public static Task<Auth_AuthorizationBase> Auth_CheckPassword(this Client client, InputCheckPasswordSRPBase password)
+		public static Task<Auth_AuthorizationBase> Auth_CheckPassword(this Client client, InputCheckPasswordSRP password)
 			=> client.CallAsync<Auth_AuthorizationBase>(writer =>
 			{
 				writer.Write(0xD18B4D16);
@@ -7129,7 +7050,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/account.getPasswordSettings"/></summary>
-		public static Task<Account_PasswordSettings> Account_GetPasswordSettings(this Client client, InputCheckPasswordSRPBase password)
+		public static Task<Account_PasswordSettings> Account_GetPasswordSettings(this Client client, InputCheckPasswordSRP password)
 			=> client.CallAsync<Account_PasswordSettings>(writer =>
 			{
 				writer.Write(0x9CD4EAF9);
@@ -7138,7 +7059,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/account.updatePasswordSettings"/></summary>
-		public static Task<bool> Account_UpdatePasswordSettings(this Client client, InputCheckPasswordSRPBase password, Account_PasswordInputSettings new_settings)
+		public static Task<bool> Account_UpdatePasswordSettings(this Client client, InputCheckPasswordSRP password, Account_PasswordInputSettings new_settings)
 			=> client.CallAsync<bool>(writer =>
 			{
 				writer.Write(0xA59B102F);
@@ -7168,7 +7089,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/account.getTmpPassword"/></summary>
-		public static Task<Account_TmpPassword> Account_GetTmpPassword(this Client client, InputCheckPasswordSRPBase password, int period)
+		public static Task<Account_TmpPassword> Account_GetTmpPassword(this Client client, InputCheckPasswordSRP password, int period)
 			=> client.CallAsync<Account_TmpPassword>(writer =>
 			{
 				writer.Write(0x449E0B51);
@@ -7457,7 +7378,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/account.createTheme"/></summary>
-		public static Task<Theme> Account_CreateTheme(this Client client, string slug, string title, InputDocumentBase document = null, InputThemeSettings settings = null)
+		public static Task<Theme> Account_CreateTheme(this Client client, string slug, string title, InputDocument document = null, InputThemeSettings settings = null)
 			=> client.CallAsync<Theme>(writer =>
 			{
 				writer.Write(0x8432C21F);
@@ -7472,7 +7393,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/account.updateTheme"/></summary>
-		public static Task<Theme> Account_UpdateTheme(this Client client, string format, InputThemeBase theme, string slug = null, string title = null, InputDocumentBase document = null, InputThemeSettings settings = null)
+		public static Task<Theme> Account_UpdateTheme(this Client client, string format, InputThemeBase theme, string slug = null, string title = null, InputDocument document = null, InputThemeSettings settings = null)
 			=> client.CallAsync<Theme>(writer =>
 			{
 				writer.Write(0x5CB367D5);
@@ -7578,7 +7499,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/account.reportProfilePhoto"/></summary>
-		public static Task<bool> Account_ReportProfilePhoto(this Client client, InputPeer peer, InputPhotoBase photo_id, ReportReason reason, string message)
+		public static Task<bool> Account_ReportProfilePhoto(this Client client, InputPeer peer, InputPhoto photo_id, ReportReason reason, string message)
 			=> client.CallAsync<bool>(writer =>
 			{
 				writer.Write(0xFA8CC6F5);
@@ -7812,7 +7733,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/contacts.getLocated"/></summary>
-		public static Task<UpdatesBase> Contacts_GetLocated(this Client client, InputGeoPointBase geo_point, bool background = false, int? self_expires = null)
+		public static Task<UpdatesBase> Contacts_GetLocated(this Client client, InputGeoPoint geo_point, bool background = false, int? self_expires = null)
 			=> client.CallAsync<UpdatesBase>(writer =>
 			{
 				writer.Write(0xD348BC44);
@@ -8416,7 +8337,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/messages.saveGif"/></summary>
-		public static Task<bool> Messages_SaveGif(this Client client, InputDocumentBase id, bool unsave)
+		public static Task<bool> Messages_SaveGif(this Client client, InputDocument id, bool unsave)
 			=> client.CallAsync<bool>(writer =>
 			{
 				writer.Write(0x327A30CB);
@@ -8426,7 +8347,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/messages.getInlineBotResults"/></summary>
-		public static Task<Messages_BotResults> Messages_GetInlineBotResults(this Client client, InputUserBase bot, InputPeer peer, string query, string offset, InputGeoPointBase geo_point = null)
+		public static Task<Messages_BotResults> Messages_GetInlineBotResults(this Client client, InputUserBase bot, InputPeer peer, string query, string offset, InputGeoPoint geo_point = null)
 			=> client.CallAsync<Messages_BotResults>(writer =>
 			{
 				writer.Write(0x514E999D);
@@ -8523,7 +8444,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/messages.getBotCallbackAnswer"/></summary>
-		public static Task<Messages_BotCallbackAnswer> Messages_GetBotCallbackAnswer(this Client client, InputPeer peer, int msg_id, bool game = false, byte[] data = null, InputCheckPasswordSRPBase password = null)
+		public static Task<Messages_BotCallbackAnswer> Messages_GetBotCallbackAnswer(this Client client, InputPeer peer, int msg_id, bool game = false, byte[] data = null, InputCheckPasswordSRP password = null)
 			=> client.CallAsync<Messages_BotCallbackAnswer>(writer =>
 			{
 				writer.Write(0x9342CA07);
@@ -8613,7 +8534,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/messages.saveRecentSticker"/></summary>
-		public static Task<bool> Messages_SaveRecentSticker(this Client client, InputDocumentBase id, bool unsave, bool attached = false)
+		public static Task<bool> Messages_SaveRecentSticker(this Client client, InputDocument id, bool unsave, bool attached = false)
 			=> client.CallAsync<bool>(writer =>
 			{
 				writer.Write(0x392718F8);
@@ -8824,7 +8745,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/messages.faveSticker"/></summary>
-		public static Task<bool> Messages_FaveSticker(this Client client, InputDocumentBase id, bool unfave)
+		public static Task<bool> Messages_FaveSticker(this Client client, InputDocument id, bool unfave)
 			=> client.CallAsync<bool>(writer =>
 			{
 				writer.Write(0xB9FFC55B);
@@ -8883,8 +8804,8 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/messages.uploadEncryptedFile"/></summary>
-		public static Task<EncryptedFileBase> Messages_UploadEncryptedFile(this Client client, InputEncryptedChat peer, InputEncryptedFileBase file)
-			=> client.CallAsync<EncryptedFileBase>(writer =>
+		public static Task<EncryptedFile> Messages_UploadEncryptedFile(this Client client, InputEncryptedChat peer, InputEncryptedFileBase file)
+			=> client.CallAsync<EncryptedFile>(writer =>
 			{
 				writer.Write(0x5057C497);
 				writer.WriteTLObject(peer);
@@ -9465,7 +9386,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/updates.getChannelDifference"/></summary>
-		public static Task<Updates_ChannelDifferenceBase> Updates_GetChannelDifference(this Client client, InputChannelBase channel, ChannelMessagesFilterBase filter, int pts, int limit, bool force = false)
+		public static Task<Updates_ChannelDifferenceBase> Updates_GetChannelDifference(this Client client, InputChannelBase channel, ChannelMessagesFilter filter, int pts, int limit, bool force = false)
 			=> client.CallAsync<Updates_ChannelDifferenceBase>(writer =>
 			{
 				writer.Write(0x03173D78);
@@ -9478,7 +9399,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/photos.updateProfilePhoto"/></summary>
-		public static Task<Photos_Photo> Photos_UpdateProfilePhoto(this Client client, InputPhotoBase id)
+		public static Task<Photos_Photo> Photos_UpdateProfilePhoto(this Client client, InputPhoto id)
 			=> client.CallAsync<Photos_Photo>(writer =>
 			{
 				writer.Write(0x72D4742C);
@@ -9502,7 +9423,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/photos.deletePhotos"/></summary>
-		public static Task<long[]> Photos_DeletePhotos(this Client client, InputPhotoBase[] id)
+		public static Task<long[]> Photos_DeletePhotos(this Client client, InputPhoto[] id)
 			=> client.CallAsync<long[]>(writer =>
 			{
 				writer.Write(0x87CF7F2F);
@@ -9704,8 +9625,8 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/help.getDeepLinkInfo"/></summary>
-		public static Task<Help_DeepLinkInfoBase> Help_GetDeepLinkInfo(this Client client, string path)
-			=> client.CallAsync<Help_DeepLinkInfoBase>(writer =>
+		public static Task<Help_DeepLinkInfo> Help_GetDeepLinkInfo(this Client client, string path)
+			=> client.CallAsync<Help_DeepLinkInfo>(writer =>
 			{
 				writer.Write(0x3FEDC75F);
 				writer.WriteTLString(path);
@@ -9747,8 +9668,8 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/help.getUserInfo"/></summary>
-		public static Task<Help_UserInfoBase> Help_GetUserInfo(this Client client, InputUserBase user_id)
-			=> client.CallAsync<Help_UserInfoBase>(writer =>
+		public static Task<Help_UserInfo> Help_GetUserInfo(this Client client, InputUserBase user_id)
+			=> client.CallAsync<Help_UserInfo>(writer =>
 			{
 				writer.Write(0x038A08D3);
 				writer.WriteTLObject(user_id);
@@ -9756,8 +9677,8 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/help.editUserInfo"/></summary>
-		public static Task<Help_UserInfoBase> Help_EditUserInfo(this Client client, InputUserBase user_id, string message, MessageEntity[] entities)
-			=> client.CallAsync<Help_UserInfoBase>(writer =>
+		public static Task<Help_UserInfo> Help_EditUserInfo(this Client client, InputUserBase user_id, string message, MessageEntity[] entities)
+			=> client.CallAsync<Help_UserInfo>(writer =>
 			{
 				writer.Write(0x66B91B70);
 				writer.WriteTLObject(user_id);
@@ -9896,7 +9817,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/channels.createChannel"/></summary>
-		public static Task<UpdatesBase> Channels_CreateChannel(this Client client, string title, string about, bool broadcast = false, bool megagroup = false, bool for_import = false, InputGeoPointBase geo_point = null, string address = null)
+		public static Task<UpdatesBase> Channels_CreateChannel(this Client client, string title, string about, bool broadcast = false, bool megagroup = false, bool for_import = false, InputGeoPoint geo_point = null, string address = null)
 			=> client.CallAsync<UpdatesBase>(writer =>
 			{
 				writer.Write(0x3D5FB10F);
@@ -10126,7 +10047,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/channels.editCreator"/></summary>
-		public static Task<UpdatesBase> Channels_EditCreator(this Client client, InputChannelBase channel, InputUserBase user_id, InputCheckPasswordSRPBase password)
+		public static Task<UpdatesBase> Channels_EditCreator(this Client client, InputChannelBase channel, InputUserBase user_id, InputCheckPasswordSRP password)
 			=> client.CallAsync<UpdatesBase>(writer =>
 			{
 				writer.Write(0x8F38CD1F);
@@ -10137,7 +10058,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/channels.editLocation"/></summary>
-		public static Task<bool> Channels_EditLocation(this Client client, InputChannelBase channel, InputGeoPointBase geo_point, string address)
+		public static Task<bool> Channels_EditLocation(this Client client, InputChannelBase channel, InputGeoPoint geo_point, string address)
 			=> client.CallAsync<bool>(writer =>
 			{
 				writer.Write(0x58E63F6D);
@@ -10325,7 +10246,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/stickers.createStickerSet"/></summary>
-		public static Task<Messages_StickerSet> Stickers_CreateStickerSet(this Client client, InputUserBase user_id, string title, string short_name, InputStickerSetItem[] stickers, bool masks = false, bool animated = false, InputDocumentBase thumb = null, string software = null)
+		public static Task<Messages_StickerSet> Stickers_CreateStickerSet(this Client client, InputUserBase user_id, string title, string short_name, InputStickerSetItem[] stickers, bool masks = false, bool animated = false, InputDocument thumb = null, string software = null)
 			=> client.CallAsync<Messages_StickerSet>(writer =>
 			{
 				writer.Write(0x9021AB67);
@@ -10342,7 +10263,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/stickers.removeStickerFromSet"/></summary>
-		public static Task<Messages_StickerSet> Stickers_RemoveStickerFromSet(this Client client, InputDocumentBase sticker)
+		public static Task<Messages_StickerSet> Stickers_RemoveStickerFromSet(this Client client, InputDocument sticker)
 			=> client.CallAsync<Messages_StickerSet>(writer =>
 			{
 				writer.Write(0xF7760F51);
@@ -10351,7 +10272,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/stickers.changeStickerPosition"/></summary>
-		public static Task<Messages_StickerSet> Stickers_ChangeStickerPosition(this Client client, InputDocumentBase sticker, int position)
+		public static Task<Messages_StickerSet> Stickers_ChangeStickerPosition(this Client client, InputDocument sticker, int position)
 			=> client.CallAsync<Messages_StickerSet>(writer =>
 			{
 				writer.Write(0xFFB6D4CA);
@@ -10371,7 +10292,7 @@ namespace TL
 			});
 
 		///<summary>See <a href="https://core.telegram.org/method/stickers.setStickerSetThumb"/></summary>
-		public static Task<Messages_StickerSet> Stickers_SetStickerSetThumb(this Client client, InputStickerSet stickerset, InputDocumentBase thumb)
+		public static Task<Messages_StickerSet> Stickers_SetStickerSetThumb(this Client client, InputStickerSet stickerset, InputDocument thumb)
 			=> client.CallAsync<Messages_StickerSet>(writer =>
 			{
 				writer.Write(0x9A364E30);
diff --git a/src/TL.Secret.cs b/src/TL.Secret.cs
index 3d7e81b..8f9e610 100644
--- a/src/TL.Secret.cs
+++ b/src/TL.Secret.cs
@@ -10,6 +10,7 @@ namespace TL
 	public abstract partial class DecryptedMessageBase : ITLObject { }
 
 	///<summary>See <a href="https://core.telegram.org/type/DecryptedMessageMedia"/></summary>
+	///<remarks>a <c>null</c> value means <a href="https://core.telegram.org/constructor/decryptedMessageMediaEmpty">decryptedMessageMediaEmpty</a></remarks>
 	public abstract partial class DecryptedMessageMedia : ITLObject { }
 
 	///<summary>See <a href="https://core.telegram.org/type/DecryptedMessageAction"/></summary>
@@ -38,9 +39,6 @@ namespace TL
 			public DecryptedMessageAction action;
 		}
 
-		///<summary>See <a href="https://core.telegram.org/constructor/decryptedMessageMediaEmpty"/></summary>
-		[TLDef(0x089F5C4A)]
-		public partial class DecryptedMessageMediaEmpty : DecryptedMessageMedia { }
 		///<summary>See <a href="https://core.telegram.org/constructor/decryptedMessageMediaPhoto"/></summary>
 		[TLDef(0x32798A8C)]
 		public partial class DecryptedMessageMediaPhoto : DecryptedMessageMedia
diff --git a/src/TL.Table.cs b/src/TL.Table.cs
index 60f0178..69f6564 100644
--- a/src/TL.Table.cs
+++ b/src/TL.Table.cs
@@ -61,22 +61,22 @@ namespace TL
 			// from TL.Schema:
 			[0x3FEDD339] = typeof(True),
 			[0xC4B9F9BB] = typeof(Error),
-			[0x56730BCC] = typeof(Null),
-			[0x7F3B18EA] = typeof(InputPeerEmpty),
+			[0x56730BCC] = null,//Null
+			[0x7F3B18EA] = null,//InputPeerEmpty
 			[0x7DA07EC9] = typeof(InputPeerSelf),
 			[0x35A95CB9] = typeof(InputPeerChat),
 			[0xDDE8A54C] = typeof(InputPeerUser),
 			[0x27BCBBFC] = typeof(InputPeerChannel),
 			[0xA87B0A1C] = typeof(InputPeerUserFromMessage),
 			[0xBD2A0840] = typeof(InputPeerChannelFromMessage),
-			[0xB98886CF] = typeof(InputUserEmpty),
+			[0xB98886CF] = null,//InputUserEmpty
 			[0xF7C1B13F] = typeof(InputUserSelf),
 			[0xF21158C6] = typeof(InputUser),
 			[0x1DA448E2] = typeof(InputUserFromMessage),
 			[0xF392B7F4] = typeof(InputPhoneContact),
 			[0xF52FF27F] = typeof(InputFile),
 			[0xFA4F0BB5] = typeof(InputFileBig),
-			[0x9664F57F] = typeof(InputMediaEmpty),
+			[0x9664F57F] = null,//InputMediaEmpty
 			[0x1E287D04] = typeof(InputMediaUploadedPhoto),
 			[0xB3BA0635] = typeof(InputMediaPhoto),
 			[0xF9C44144] = typeof(InputMediaGeoPoint),
@@ -91,12 +91,12 @@ namespace TL
 			[0x971FA843] = typeof(InputMediaGeoLive),
 			[0x0F94E5F1] = typeof(InputMediaPoll),
 			[0xE66FBF7B] = typeof(InputMediaDice),
-			[0x1CA48F57] = typeof(InputChatPhotoEmpty),
+			[0x1CA48F57] = null,//InputChatPhotoEmpty
 			[0xC642724E] = typeof(InputChatUploadedPhoto),
 			[0x8953AD37] = typeof(InputChatPhoto),
-			[0xE4C123D6] = typeof(InputGeoPointEmpty),
+			[0xE4C123D6] = null,//InputGeoPointEmpty
 			[0x48222FAF] = typeof(InputGeoPoint),
-			[0x1CD7BF0D] = typeof(InputPhotoEmpty),
+			[0x1CD7BF0D] = null,//InputPhotoEmpty
 			[0x3BB3B94A] = typeof(InputPhoto),
 			[0xDFDAABE1] = typeof(InputFileLocation),
 			[0xF5235D55] = typeof(InputEncryptedFileLocation),
@@ -113,9 +113,9 @@ namespace TL
 			[0xA2A5371E] = typeof(PeerChannel),
 			[0xD3BC4B7A] = typeof(UserEmpty),
 			[0x3FF6ECB0] = typeof(User),
-			[0x4F11BAE1] = typeof(UserProfilePhotoEmpty),
+			[0x4F11BAE1] = null,//UserProfilePhotoEmpty
 			[0x82D1F706] = typeof(UserProfilePhoto),
-			[0x09D05049] = typeof(UserStatusEmpty),
+			[0x09D05049] = null,//UserStatusEmpty
 			[0xEDB93949] = typeof(UserStatusOnline),
 			[0x008C703F] = typeof(UserStatusOffline),
 			[0xE26F42F1] = typeof(UserStatusRecently),
@@ -133,12 +133,12 @@ namespace TL
 			[0xA0933F5B] = typeof(ChatParticipantAdmin),
 			[0x8763D3E1] = typeof(ChatParticipantsForbidden),
 			[0x3CBC93F8] = typeof(ChatParticipants),
-			[0x37C1011C] = typeof(ChatPhotoEmpty),
+			[0x37C1011C] = null,//ChatPhotoEmpty
 			[0x1C6E1C11] = typeof(ChatPhoto),
 			[0x90A6CA84] = typeof(MessageEmpty),
 			[0x85D6CBE2] = typeof(Message),
 			[0x2B085862] = typeof(MessageService),
-			[0x3DED6320] = typeof(MessageMediaEmpty),
+			[0x3DED6320] = null,//MessageMediaEmpty
 			[0x695150D7] = typeof(MessageMediaPhoto),
 			[0x56E0D474] = typeof(MessageMediaGeo),
 			[0x70322949] = typeof(MessageMediaContact),
@@ -151,7 +151,7 @@ namespace TL
 			[0xB940C666] = typeof(MessageMediaGeoLive),
 			[0x4BD6E798] = typeof(MessageMediaPoll),
 			[0x3F7EE58B] = typeof(MessageMediaDice),
-			[0xB6AEF7B0] = typeof(MessageActionEmpty),
+			[0xB6AEF7B0] = null,//MessageActionEmpty
 			[0xBD47CBAD] = typeof(MessageActionChatCreate),
 			[0xB5A1CE5A] = typeof(MessageActionChatEditTitle),
 			[0x7FCB13A8] = typeof(MessageActionChatEditPhoto),
@@ -190,7 +190,7 @@ namespace TL
 			[0xE0B0BC2E] = typeof(PhotoStrippedSize),
 			[0xFA3EFB95] = typeof(PhotoSizeProgressive),
 			[0xD8214D41] = typeof(PhotoPathSize),
-			[0x1117DD5F] = typeof(GeoPointEmpty),
+			[0x1117DD5F] = null,//GeoPointEmpty
 			[0xB2A2F663] = typeof(GeoPoint),
 			[0x5E002502] = typeof(Auth_SentCode),
 			[0xCD050916] = typeof(Auth_Authorization),
@@ -225,7 +225,7 @@ namespace TL
 			[0x9CD81144] = typeof(Messages_ChatsSlice),
 			[0xE5D7D19C] = typeof(Messages_ChatFull),
 			[0xB45C69D1] = typeof(Messages_AffectedHistory),
-			[0x57E2F66C] = typeof(InputMessagesFilterEmpty),
+			[0x57E2F66C] = null,//InputMessagesFilterEmpty
 			[0x9609A51C] = typeof(InputMessagesFilterPhotos),
 			[0x9FC00E65] = typeof(InputMessagesFilterVideo),
 			[0x56E9F0E4] = typeof(InputMessagesFilterPhotoVideo),
@@ -364,9 +364,9 @@ namespace TL
 			[0x61F0D4C7] = typeof(EncryptedChat),
 			[0x1E1C7C45] = typeof(EncryptedChatDiscarded),
 			[0xF141B5E1] = typeof(InputEncryptedChat),
-			[0xC21F497E] = typeof(EncryptedFileEmpty),
+			[0xC21F497E] = null,//EncryptedFileEmpty
 			[0x4A70994C] = typeof(EncryptedFile),
-			[0x1837C364] = typeof(InputEncryptedFileEmpty),
+			[0x1837C364] = null,//InputEncryptedFileEmpty
 			[0x64BD0306] = typeof(InputEncryptedFileUploaded),
 			[0x5A17B5E5] = typeof(InputEncryptedFile),
 			[0x2DC173C8] = typeof(InputEncryptedFileBigUploaded),
@@ -376,7 +376,7 @@ namespace TL
 			[0x2C221EDD] = typeof(Messages_DhConfig),
 			[0x560F8935] = typeof(Messages_SentEncryptedMessage),
 			[0x9493FF32] = typeof(Messages_SentEncryptedFile),
-			[0x72F0EAAE] = typeof(InputDocumentEmpty),
+			[0x72F0EAAE] = null,//InputDocumentEmpty
 			[0x1ABFB575] = typeof(InputDocument),
 			[0x36F8C871] = typeof(DocumentEmpty),
 			[0x1E87342B] = typeof(Document),
@@ -450,7 +450,7 @@ namespace TL
 			[0x5A686D7C] = typeof(ChatInviteAlready),
 			[0xDFC2F58E] = typeof(ChatInvite),
 			[0x61695CB0] = typeof(ChatInvitePeek),
-			[0xFFB62B95] = typeof(InputStickerSetEmpty),
+			[0xFFB62B95] = null,//InputStickerSetEmpty
 			[0x9DE7A269] = typeof(InputStickerSetID),
 			[0x861CC8A0] = typeof(InputStickerSetShortName),
 			[0x028703C8] = typeof(InputStickerSetAnimatedEmoji),
@@ -494,7 +494,7 @@ namespace TL
 			[0xBF0693D4] = typeof(MessageEntityStrike),
 			[0x020DF5D0] = typeof(MessageEntityBlockquote),
 			[0x761E6AF4] = typeof(MessageEntityBankCard),
-			[0xEE8C1E86] = typeof(InputChannelEmpty),
+			[0xEE8C1E86] = null,//InputChannelEmpty
 			[0xF35AEC28] = typeof(InputChannel),
 			[0x5B934F9D] = typeof(InputChannelFromMessage),
 			[0x7F077AD9] = typeof(Contacts_ResolvedPeer),
@@ -502,7 +502,7 @@ namespace TL
 			[0x3E11AFFB] = typeof(Updates_ChannelDifferenceEmpty),
 			[0xA4BCC6FE] = typeof(Updates_ChannelDifferenceTooLong),
 			[0x2064674E] = typeof(Updates_ChannelDifference),
-			[0x94D42EE7] = typeof(ChannelMessagesFilterEmpty),
+			[0x94D42EE7] = null,//ChannelMessagesFilterEmpty
 			[0xCD77D957] = typeof(ChannelMessagesFilter),
 			[0xC00C07C0] = typeof(ChannelParticipant),
 			[0x28A8BC67] = typeof(ChannelParticipantSelf),
@@ -580,7 +580,7 @@ namespace TL
 			[0xC331E80A] = typeof(InputGameShortName),
 			[0x73A379EB] = typeof(HighScore),
 			[0x9A3BFD99] = typeof(Messages_HighScores),
-			[0xDC3D824F] = typeof(TextEmpty),
+			[0xDC3D824F] = null,//TextEmpty
 			[0x744694E0] = typeof(TextPlain),
 			[0x6724ABC4] = typeof(TextBold),
 			[0xD912A59C] = typeof(TextItalic),
@@ -735,7 +735,7 @@ namespace TL
 			[0x28ECF961] = typeof(Help_TermsOfServiceUpdate),
 			[0x3334B0F0] = typeof(InputSecureFileUploaded),
 			[0x5367E5BE] = typeof(InputSecureFile),
-			[0x64199744] = typeof(SecureFileEmpty),
+			[0x64199744] = null,//SecureFileEmpty
 			[0xE0277A62] = typeof(SecureFile),
 			[0x8AEABEC3] = typeof(SecureData),
 			[0x7D6099DD] = typeof(SecurePlainPhone),
@@ -755,17 +755,17 @@ namespace TL
 			[0x33F0EA47] = typeof(SecureCredentialsEncrypted),
 			[0xAD2E1CD8] = typeof(Account_AuthorizationForm),
 			[0x811F854F] = typeof(Account_SentEmailCode),
-			[0x66AFA166] = typeof(Help_DeepLinkInfoEmpty),
+			[0x66AFA166] = null,//Help_DeepLinkInfoEmpty
 			[0x6A4EE832] = typeof(Help_DeepLinkInfo),
 			[0x1142BD56] = typeof(SavedPhoneContact),
 			[0x4DBA4501] = typeof(Account_Takeout),
-			[0xD45AB096] = typeof(PasswordKdfAlgoUnknown),
+			[0xD45AB096] = null,//PasswordKdfAlgoUnknown
 			[0x3A912D4A] = typeof(PasswordKdfAlgoSHA256SHA256PBKDF2HMACSHA512iter100000SHA256ModPow),
-			[0x004A8537] = typeof(SecurePasswordKdfAlgoUnknown),
+			[0x004A8537] = null,//SecurePasswordKdfAlgoUnknown
 			[0xBBF2DDA0] = typeof(SecurePasswordKdfAlgoPBKDF2HMACSHA512iter100000),
 			[0x86471D92] = typeof(SecurePasswordKdfAlgoSHA512),
 			[0x1527BCAC] = typeof(SecureSecretSettings),
-			[0x9880F658] = typeof(InputCheckPasswordEmpty),
+			[0x9880F658] = null,//InputCheckPasswordEmpty
 			[0xD27FF082] = typeof(InputCheckPasswordSRP),
 			[0x829D99DA] = typeof(SecureRequiredType),
 			[0x027477B4] = typeof(SecureRequiredTypeOneOf),
@@ -789,7 +789,7 @@ namespace TL
 			[0xB390DC08] = typeof(PageRelatedArticle),
 			[0x98657F0D] = typeof(Page),
 			[0x8C05F1C9] = typeof(Help_SupportName),
-			[0xF3AE2EED] = typeof(Help_UserInfoEmpty),
+			[0xF3AE2EED] = null,//Help_UserInfoEmpty
 			[0x01EB3758] = typeof(Help_UserInfo),
 			[0x6CA9C2E9] = typeof(PollAnswer),
 			[0x86E18161] = typeof(Poll),
@@ -820,7 +820,7 @@ namespace TL
 			[0x92D33A0E] = typeof(UrlAuthResultRequest),
 			[0x8F8C0E4E] = typeof(UrlAuthResultAccepted),
 			[0xA9D6DB1F] = typeof(UrlAuthResultDefault),
-			[0xBFB5AD8B] = typeof(ChannelLocationEmpty),
+			[0xBFB5AD8B] = null,//ChannelLocationEmpty
 			[0x209B82DB] = typeof(ChannelLocation),
 			[0xCA461B5D] = typeof(PeerLocated),
 			[0xF8EC284B] = typeof(PeerSelfLocated),
@@ -911,23 +911,18 @@ namespace TL
 			[0x2A3C381F] = typeof(SponsoredMessage),
 			[0x65A4C7D5] = typeof(Messages_SponsoredMessages),
 			// from TL.Secret:
-			[0x91CC4674] = typeof(Layer73.DecryptedMessage),
 			[0xBB718624] = typeof(Layer66.SendMessageUploadRoundAction),
 			[0xE50511D8] = typeof(Layer45.DecryptedMessageMediaWebPage),
 			[0x8A0DF56F] = typeof(Layer45.DecryptedMessageMediaVenue),
-			[0xDED218E0] = typeof(Layer45.DocumentAttributeAudio),
-			[0x3A556302] = typeof(Layer45.DocumentAttributeSticker),
-			[0x7AFE8AE2] = typeof(Layer45.DecryptedMessageMediaDocument),
-			[0x970C8C0E] = typeof(Layer45.DecryptedMessageMediaVideo),
-			[0xF1FA8D78] = typeof(Layer45.DecryptedMessageMediaPhoto),
-			[0x36B091DE] = typeof(Layer45.DecryptedMessage),
 			[0xFA95B0DD] = typeof(Layer23.DecryptedMessageMediaExternalDocument),
 			[0x53D69076] = typeof(Layer23.FileLocation),
 			[0x7C596B46] = typeof(Layer23.FileLocationUnavailable),
 			[0xE9A734FA] = typeof(Layer23.PhotoCachedSize),
 			[0x77BFB61B] = typeof(Layer23.PhotoSize),
+			[0xDED218E0] = typeof(Layer45.DocumentAttributeAudio),
 			[0x051448E5] = typeof(Layer23.DocumentAttributeAudio),
 			[0x5910CCCB] = typeof(Layer23.DocumentAttributeVideo),
+			[0x3A556302] = typeof(Layer45.DocumentAttributeSticker),
 			[0xFB0A5727] = typeof(Layer23.DocumentAttributeSticker),
 			[0xA82FDD63] = typeof(Layer20.DecryptedMessageActionNoop),
 			[0xEC2E0B9B] = typeof(Layer20.DecryptedMessageActionCommitKey),
@@ -942,25 +937,67 @@ namespace TL
 			[0xE6AC8A6F] = typeof(Layer17.SendMessageUploadAudioAction),
 			[0x92042FF7] = typeof(Layer17.SendMessageUploadVideoAction),
 			[0x1BE31789] = typeof(Layer17.DecryptedMessageLayer),
-			[0x57E0A9CB] = typeof(Layer17.DecryptedMessageMediaAudio),
-			[0x524A415D] = typeof(Layer17.DecryptedMessageMediaVideo),
-			[0x73164160] = typeof(Layer17.DecryptedMessageService),
-			[0x204D3878] = typeof(Layer17.DecryptedMessage),
 			[0x6719E45C] = typeof(Layer8.DecryptedMessageActionFlushHistory),
 			[0x8AC1F475] = typeof(Layer8.DecryptedMessageActionScreenshotMessages),
 			[0x65614304] = typeof(Layer8.DecryptedMessageActionDeleteMessages),
 			[0x0C4F40BE] = typeof(Layer8.DecryptedMessageActionReadMessages),
+			[0x57E0A9CB] = typeof(Layer17.DecryptedMessageMediaAudio),
 			[0x6080758F] = typeof(Layer8.DecryptedMessageMediaAudio),
+			[0x7AFE8AE2] = typeof(Layer45.DecryptedMessageMediaDocument),
 			[0xB095434B] = typeof(Layer8.DecryptedMessageMediaDocument),
 			[0xA1733AEC] = typeof(Layer8.DecryptedMessageActionSetMessageTTL),
 			[0x588A0A97] = typeof(Layer8.DecryptedMessageMediaContact),
 			[0x35480A59] = typeof(Layer8.DecryptedMessageMediaGeoPoint),
+			[0x970C8C0E] = typeof(Layer45.DecryptedMessageMediaVideo),
+			[0x524A415D] = typeof(Layer17.DecryptedMessageMediaVideo),
 			[0x4CEE6EF3] = typeof(Layer8.DecryptedMessageMediaVideo),
+			[0xF1FA8D78] = typeof(Layer45.DecryptedMessageMediaPhoto),
 			[0x32798A8C] = typeof(Layer8.DecryptedMessageMediaPhoto),
-			[0x089F5C4A] = typeof(Layer8.DecryptedMessageMediaEmpty),
+			[0x089F5C4A] = null,//Layer8.DecryptedMessageMediaEmpty
+			[0x73164160] = typeof(Layer17.DecryptedMessageService),
 			[0xAA48327D] = typeof(Layer8.DecryptedMessageService),
+			[0x91CC4674] = typeof(Layer73.DecryptedMessage),
+			[0x36B091DE] = typeof(Layer45.DecryptedMessage),
+			[0x204D3878] = typeof(Layer17.DecryptedMessage),
 			[0x1F814F1F] = typeof(Layer8.DecryptedMessage),
 			// The End
 		};
+
+		internal readonly static Dictionary<Type, uint> Nullables = new()
+		{
+			// from TL.MTProto:
+			// from TL.Schema:
+			[typeof(Null)]                           = 0x56730BCC, //null
+			[typeof(InputPeer)]                      = 0x7F3B18EA, //inputPeerEmpty
+			[typeof(InputUserBase)]                  = 0xB98886CF, //inputUserEmpty
+			[typeof(InputMedia)]                     = 0x9664F57F, //inputMediaEmpty
+			[typeof(InputChatPhotoBase)]             = 0x1CA48F57, //inputChatPhotoEmpty
+			[typeof(InputGeoPoint)]                  = 0xE4C123D6, //inputGeoPointEmpty
+			[typeof(InputPhoto)]                     = 0x1CD7BF0D, //inputPhotoEmpty
+			[typeof(UserProfilePhoto)]               = 0x4F11BAE1, //userProfilePhotoEmpty
+			[typeof(UserStatus)]                     = 0x09D05049, //userStatusEmpty
+			[typeof(ChatPhoto)]                      = 0x37C1011C, //chatPhotoEmpty
+			[typeof(MessageMedia)]                   = 0x3DED6320, //messageMediaEmpty
+			[typeof(MessageAction)]                  = 0xB6AEF7B0, //messageActionEmpty
+			[typeof(GeoPoint)]                       = 0x1117DD5F, //geoPointEmpty
+			[typeof(MessagesFilter)]                 = 0x57E2F66C, //inputMessagesFilterEmpty
+			[typeof(EncryptedFile)]                  = 0xC21F497E, //encryptedFileEmpty
+			[typeof(InputEncryptedFileBase)]         = 0x1837C364, //inputEncryptedFileEmpty
+			[typeof(InputDocument)]                  = 0x72F0EAAE, //inputDocumentEmpty
+			[typeof(InputStickerSet)]                = 0xFFB62B95, //inputStickerSetEmpty
+			[typeof(InputChannelBase)]               = 0xEE8C1E86, //inputChannelEmpty
+			[typeof(ChannelMessagesFilter)]          = 0x94D42EE7, //channelMessagesFilterEmpty
+			[typeof(RichText)]                       = 0xDC3D824F, //textEmpty
+			[typeof(SecureFile)]                     = 0x64199744, //secureFileEmpty
+			[typeof(Help_DeepLinkInfo)]              = 0x66AFA166, //help.deepLinkInfoEmpty
+			[typeof(PasswordKdfAlgo)]                = 0xD45AB096, //passwordKdfAlgoUnknown
+			[typeof(SecurePasswordKdfAlgo)]          = 0x004A8537, //securePasswordKdfAlgoUnknown
+			[typeof(InputCheckPasswordSRP)]          = 0x9880F658, //inputCheckPasswordEmpty
+			[typeof(Help_UserInfo)]                  = 0xF3AE2EED, //help.userInfoEmpty
+			[typeof(ChannelLocation)]                = 0xBFB5AD8B, //channelLocationEmpty
+			// from TL.Secret:
+			[typeof(DecryptedMessageMedia)]          = 0x089F5C4A, //decryptedMessageMediaEmpty
+			// The End
+		};
 	}
 }
diff --git a/src/TL.cs b/src/TL.cs
index 9e1099e..0cb701c 100644
--- a/src/TL.cs
+++ b/src/TL.cs
@@ -29,9 +29,9 @@ namespace TL
 			return (T)reader.ReadTLObject();
 		}
 
-		internal static void WriteTLObject(this BinaryWriter writer, ITLObject obj)
+		internal static void WriteTLObject<T>(this BinaryWriter writer, T obj) where T : ITLObject
 		{
-			if (obj == null) { writer.Write(Layer.NullCtor); return; }
+			if (obj == null) { writer.WriteTLNull(typeof(T)); return; }
 			var type = obj.GetType();
 			var tlDef = type.GetCustomAttribute<TLDefAttribute>();
 			var ctorNb = tlDef.CtorNb;
@@ -44,10 +44,7 @@ namespace TL
 			{
 				if (((ifFlag = field.GetCustomAttribute<IfFlagAttribute>()) != null) && (flags & (1 << ifFlag.Bit)) == 0) continue;
 				object value = field.GetValue(obj);
-				if (value == null)
-					writer.WriteTLNull(field.FieldType);
-				else
-					writer.WriteTLValue(value);
+				writer.WriteTLValue(value, field.FieldType);
 				if (field.Name.Equals("Flags", StringComparison.OrdinalIgnoreCase)) flags = (int)value;
 			}
 		}
@@ -55,9 +52,9 @@ namespace TL
 		internal static ITLObject ReadTLObject(this BinaryReader reader, uint ctorNb = 0)
 		{
 			if (ctorNb == 0) ctorNb = reader.ReadUInt32();
-			if (ctorNb == Layer.NullCtor) return null;
 			if (!Layer.Table.TryGetValue(ctorNb, out var type))
 				throw new ApplicationException($"Cannot find type for ctor #{ctorNb:x}");
+			if (type == null) return null; // nullable ctor (class meaning is associated with null)
 			var tlDef = type.GetCustomAttribute<TLDefAttribute>();
 			var obj = Activator.CreateInstance(type);
 			IEnumerable<FieldInfo> fields = type.GetFields();
@@ -75,8 +72,13 @@ namespace TL
 			return type == typeof(GzipPacked) ? UnzipPacket((GzipPacked)obj, reader.Client) : (ITLObject)obj;
 		}
 
-		internal static void WriteTLValue(this BinaryWriter writer, object value)
+		internal static void WriteTLValue(this BinaryWriter writer, object value, Type valueType)
 		{
+			if (value == null)
+			{
+				writer.WriteTLNull(valueType);
+				return;
+			}
 			var type = value.GetType();
 			switch (Type.GetTypeCode(type))
 			{
@@ -153,8 +155,9 @@ namespace TL
 			if (array == null) { writer.Write(0); return; }
 			int count = array.Length;
 			writer.Write(count);
+			var elementType = array.GetType().GetElementType();
 			for (int i = 0; i < count; i++)
-				writer.WriteTLValue(array.GetValue(i));
+				writer.WriteTLValue(array.GetValue(i), elementType);
 		}
 
 		internal static Array ReadTLVector(this BinaryReader reader, Type type)
@@ -232,7 +235,11 @@ namespace TL
 		internal static void WriteTLNull(this BinaryWriter writer, Type type)
 		{
 			if (type == typeof(string)) { }
-			else if (!type.IsArray) { writer.Write(Layer.NullCtor); return; }
+			else if (!type.IsArray)
+			{
+				writer.Write(Layer.Nullables.TryGetValue(type, out uint nullCtor) ? nullCtor : Layer.NullCtor);
+				return;
+			}
 			else if (type != typeof(byte[]))
 				writer.Write(Layer.VectorCtor); // not raw bytes but a vector => needs a VectorCtor
 			writer.Write(0);    // null arrays/strings are serialized as empty