diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0088248b..1e2d9c67 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -420,6 +420,7 @@ set(TDLIB_SOURCE
   td/telegram/Location.cpp
   td/telegram/Logging.cpp
   td/telegram/MessageContent.cpp
+  td/telegram/MessageContentType.cpp
   td/telegram/MessageEntity.cpp
   td/telegram/MessageId.cpp
   td/telegram/MessagesDb.cpp
@@ -582,6 +583,7 @@ set(TDLIB_SOURCE
   td/telegram/logevent/SecretChatEvent.h
   td/telegram/Logging.h
   td/telegram/MessageContent.h
+  td/telegram/MessageContentType.h
   td/telegram/MessageEntity.h
   td/telegram/MessageId.h
   td/telegram/MessagesDb.h
diff --git a/td/telegram/MessageContent.cpp b/td/telegram/MessageContent.cpp
index 0d71ff8d..330eb25e 100644
--- a/td/telegram/MessageContent.cpp
+++ b/td/telegram/MessageContent.cpp
@@ -643,98 +643,6 @@ class MessagePoll : public MessageContent {
   }
 };
 
-StringBuilder &operator<<(StringBuilder &string_builder, MessageContentType content_type) {
-  switch (content_type) {
-    case MessageContentType::None:
-      return string_builder << "None";
-    case MessageContentType::Animation:
-      return string_builder << "Animation";
-    case MessageContentType::Audio:
-      return string_builder << "Audio";
-    case MessageContentType::Document:
-      return string_builder << "Document";
-    case MessageContentType::ExpiredPhoto:
-      return string_builder << "ExpiredPhoto";
-    case MessageContentType::Photo:
-      return string_builder << "Photo";
-    case MessageContentType::ExpiredVideo:
-      return string_builder << "ExpiredVideo";
-    case MessageContentType::Video:
-      return string_builder << "Video";
-    case MessageContentType::VideoNote:
-      return string_builder << "VideoNote";
-    case MessageContentType::VoiceNote:
-      return string_builder << "VoiceNote";
-    case MessageContentType::Contact:
-      return string_builder << "Contact";
-    case MessageContentType::LiveLocation:
-      return string_builder << "LiveLocation";
-    case MessageContentType::Location:
-      return string_builder << "Location";
-    case MessageContentType::Venue:
-      return string_builder << "Venue";
-    case MessageContentType::Game:
-      return string_builder << "Game";
-    case MessageContentType::Invoice:
-      return string_builder << "Invoice";
-    case MessageContentType::Sticker:
-      return string_builder << "Sticker";
-    case MessageContentType::Text:
-      return string_builder << "Text";
-    case MessageContentType::Unsupported:
-      return string_builder << "Unsupported";
-    case MessageContentType::ChatCreate:
-      return string_builder << "ChatCreate";
-    case MessageContentType::ChatChangeTitle:
-      return string_builder << "ChatChangeTitle";
-    case MessageContentType::ChatChangePhoto:
-      return string_builder << "ChatChangePhoto";
-    case MessageContentType::ChatDeletePhoto:
-      return string_builder << "ChatDeletePhoto";
-    case MessageContentType::ChatDeleteHistory:
-      return string_builder << "ChatDeleteHistory";
-    case MessageContentType::ChatAddUsers:
-      return string_builder << "ChatAddUsers";
-    case MessageContentType::ChatJoinedByLink:
-      return string_builder << "ChatJoinedByLink";
-    case MessageContentType::ChatDeleteUser:
-      return string_builder << "ChatDeleteUser";
-    case MessageContentType::ChatMigrateTo:
-      return string_builder << "ChatMigrateTo";
-    case MessageContentType::ChannelCreate:
-      return string_builder << "ChannelCreate";
-    case MessageContentType::ChannelMigrateFrom:
-      return string_builder << "ChannelMigrateFrom";
-    case MessageContentType::PinMessage:
-      return string_builder << "PinMessage";
-    case MessageContentType::GameScore:
-      return string_builder << "GameScore";
-    case MessageContentType::ScreenshotTaken:
-      return string_builder << "ScreenshotTaken";
-    case MessageContentType::ChatSetTtl:
-      return string_builder << "ChatSetTtl";
-    case MessageContentType::Call:
-      return string_builder << "Call";
-    case MessageContentType::PaymentSuccessful:
-      return string_builder << "PaymentSuccessful";
-    case MessageContentType::ContactRegistered:
-      return string_builder << "ContactRegistered";
-    case MessageContentType::CustomServiceAction:
-      return string_builder << "CustomServiceAction";
-    case MessageContentType::WebsiteConnected:
-      return string_builder << "WebsiteConnected";
-    case MessageContentType::PassportDataSent:
-      return string_builder << "PassportDataSent";
-    case MessageContentType::PassportDataReceived:
-      return string_builder << "PassportDataReceived";
-    case MessageContentType::Poll:
-      return string_builder << "Poll";
-    default:
-      UNREACHABLE();
-      return string_builder;
-  }
-}
-
 template <class StorerT>
 static void store(const MessageContent *content, StorerT &storer) {
   CHECK(content != nullptr);
@@ -2399,57 +2307,6 @@ void delete_message_content_thumbnail(MessageContent *content, Td *td) {
   }
 }
 
-bool is_allowed_media_group_content(MessageContentType content_type) {
-  switch (content_type) {
-    case MessageContentType::Photo:
-    case MessageContentType::Video:
-    case MessageContentType::ExpiredPhoto:
-    case MessageContentType::ExpiredVideo:
-      return true;
-    case MessageContentType::Animation:
-    case MessageContentType::Audio:
-    case MessageContentType::Contact:
-    case MessageContentType::Document:
-    case MessageContentType::Game:
-    case MessageContentType::Invoice:
-    case MessageContentType::LiveLocation:
-    case MessageContentType::Location:
-    case MessageContentType::Sticker:
-    case MessageContentType::Text:
-    case MessageContentType::Unsupported:
-    case MessageContentType::Venue:
-    case MessageContentType::VideoNote:
-    case MessageContentType::VoiceNote:
-    case MessageContentType::ChatCreate:
-    case MessageContentType::ChatChangeTitle:
-    case MessageContentType::ChatChangePhoto:
-    case MessageContentType::ChatDeletePhoto:
-    case MessageContentType::ChatDeleteHistory:
-    case MessageContentType::ChatAddUsers:
-    case MessageContentType::ChatJoinedByLink:
-    case MessageContentType::ChatDeleteUser:
-    case MessageContentType::ChatMigrateTo:
-    case MessageContentType::ChannelCreate:
-    case MessageContentType::ChannelMigrateFrom:
-    case MessageContentType::PinMessage:
-    case MessageContentType::GameScore:
-    case MessageContentType::ScreenshotTaken:
-    case MessageContentType::ChatSetTtl:
-    case MessageContentType::Call:
-    case MessageContentType::PaymentSuccessful:
-    case MessageContentType::ContactRegistered:
-    case MessageContentType::CustomServiceAction:
-    case MessageContentType::WebsiteConnected:
-    case MessageContentType::PassportDataSent:
-    case MessageContentType::PassportDataReceived:
-    case MessageContentType::Poll:
-      return false;
-    default:
-      UNREACHABLE();
-      return false;
-  }
-}
-
 bool can_forward_message_content(const MessageContent *content) {
   auto content_type = content->get_type();
   if (content_type == MessageContentType::Text) {
@@ -2465,162 +2322,6 @@ bool can_forward_message_content(const MessageContent *content) {
          content_type != MessageContentType::ExpiredPhoto && content_type != MessageContentType::ExpiredVideo;
 }
 
-bool is_secret_message_content(int32 ttl, MessageContentType content_type) {
-  if (ttl <= 0 || ttl > 60) {
-    return false;
-  }
-  switch (content_type) {
-    case MessageContentType::Animation:
-    case MessageContentType::Audio:
-    case MessageContentType::Photo:
-    case MessageContentType::Video:
-    case MessageContentType::VideoNote:
-    case MessageContentType::VoiceNote:
-      return true;
-    case MessageContentType::Contact:
-    case MessageContentType::Document:
-    case MessageContentType::Game:
-    case MessageContentType::Invoice:
-    case MessageContentType::LiveLocation:
-    case MessageContentType::Location:
-    case MessageContentType::Sticker:
-    case MessageContentType::Text:
-    case MessageContentType::Unsupported:
-    case MessageContentType::Venue:
-    case MessageContentType::ExpiredPhoto:
-    case MessageContentType::ExpiredVideo:
-    case MessageContentType::ChatCreate:
-    case MessageContentType::ChatChangeTitle:
-    case MessageContentType::ChatChangePhoto:
-    case MessageContentType::ChatDeletePhoto:
-    case MessageContentType::ChatDeleteHistory:
-    case MessageContentType::ChatAddUsers:
-    case MessageContentType::ChatJoinedByLink:
-    case MessageContentType::ChatDeleteUser:
-    case MessageContentType::ChatMigrateTo:
-    case MessageContentType::ChannelCreate:
-    case MessageContentType::ChannelMigrateFrom:
-    case MessageContentType::PinMessage:
-    case MessageContentType::GameScore:
-    case MessageContentType::ScreenshotTaken:
-    case MessageContentType::ChatSetTtl:
-    case MessageContentType::Call:
-    case MessageContentType::PaymentSuccessful:
-    case MessageContentType::ContactRegistered:
-    case MessageContentType::CustomServiceAction:
-    case MessageContentType::WebsiteConnected:
-    case MessageContentType::PassportDataSent:
-    case MessageContentType::PassportDataReceived:
-    case MessageContentType::Poll:
-      return false;
-    default:
-      UNREACHABLE();
-      return false;
-  }
-}
-
-bool is_service_message_content(MessageContentType content_type) {
-  switch (content_type) {
-    case MessageContentType::Animation:
-    case MessageContentType::Audio:
-    case MessageContentType::Contact:
-    case MessageContentType::Document:
-    case MessageContentType::Game:
-    case MessageContentType::Invoice:
-    case MessageContentType::LiveLocation:
-    case MessageContentType::Location:
-    case MessageContentType::Photo:
-    case MessageContentType::Sticker:
-    case MessageContentType::Text:
-    case MessageContentType::Unsupported:
-    case MessageContentType::Venue:
-    case MessageContentType::Video:
-    case MessageContentType::VideoNote:
-    case MessageContentType::VoiceNote:
-    case MessageContentType::ExpiredPhoto:
-    case MessageContentType::ExpiredVideo:
-    case MessageContentType::Poll:
-      return false;
-    case MessageContentType::ChatCreate:
-    case MessageContentType::ChatChangeTitle:
-    case MessageContentType::ChatChangePhoto:
-    case MessageContentType::ChatDeletePhoto:
-    case MessageContentType::ChatDeleteHistory:
-    case MessageContentType::ChatAddUsers:
-    case MessageContentType::ChatJoinedByLink:
-    case MessageContentType::ChatDeleteUser:
-    case MessageContentType::ChatMigrateTo:
-    case MessageContentType::ChannelCreate:
-    case MessageContentType::ChannelMigrateFrom:
-    case MessageContentType::PinMessage:
-    case MessageContentType::GameScore:
-    case MessageContentType::ScreenshotTaken:
-    case MessageContentType::ChatSetTtl:
-    case MessageContentType::Call:
-    case MessageContentType::PaymentSuccessful:
-    case MessageContentType::ContactRegistered:
-    case MessageContentType::CustomServiceAction:
-    case MessageContentType::WebsiteConnected:
-    case MessageContentType::PassportDataSent:
-    case MessageContentType::PassportDataReceived:
-      return true;
-    default:
-      UNREACHABLE();
-      return false;
-  }
-}
-
-bool can_have_message_content_caption(MessageContentType content_type) {
-  switch (content_type) {
-    case MessageContentType::Animation:
-    case MessageContentType::Audio:
-    case MessageContentType::Document:
-    case MessageContentType::Photo:
-    case MessageContentType::Video:
-    case MessageContentType::VoiceNote:
-      return true;
-    case MessageContentType::Contact:
-    case MessageContentType::Game:
-    case MessageContentType::Invoice:
-    case MessageContentType::LiveLocation:
-    case MessageContentType::Location:
-    case MessageContentType::Sticker:
-    case MessageContentType::Text:
-    case MessageContentType::Unsupported:
-    case MessageContentType::Venue:
-    case MessageContentType::VideoNote:
-    case MessageContentType::ChatCreate:
-    case MessageContentType::ChatChangeTitle:
-    case MessageContentType::ChatChangePhoto:
-    case MessageContentType::ChatDeletePhoto:
-    case MessageContentType::ChatDeleteHistory:
-    case MessageContentType::ChatAddUsers:
-    case MessageContentType::ChatJoinedByLink:
-    case MessageContentType::ChatDeleteUser:
-    case MessageContentType::ChatMigrateTo:
-    case MessageContentType::ChannelCreate:
-    case MessageContentType::ChannelMigrateFrom:
-    case MessageContentType::PinMessage:
-    case MessageContentType::GameScore:
-    case MessageContentType::ScreenshotTaken:
-    case MessageContentType::ChatSetTtl:
-    case MessageContentType::Call:
-    case MessageContentType::PaymentSuccessful:
-    case MessageContentType::ContactRegistered:
-    case MessageContentType::ExpiredPhoto:
-    case MessageContentType::ExpiredVideo:
-    case MessageContentType::CustomServiceAction:
-    case MessageContentType::WebsiteConnected:
-    case MessageContentType::PassportDataSent:
-    case MessageContentType::PassportDataReceived:
-    case MessageContentType::Poll:
-      return false;
-    default:
-      UNREACHABLE();
-      return false;
-  }
-}
-
 bool update_opened_message_content(MessageContent *content) {
   switch (content->get_type()) {
     case MessageContentType::VideoNote: {
diff --git a/td/telegram/MessageContent.h b/td/telegram/MessageContent.h
index 8e450a90..87b40875 100644
--- a/td/telegram/MessageContent.h
+++ b/td/telegram/MessageContent.h
@@ -11,6 +11,7 @@
 #include "td/telegram/files/FileId.h"
 #include "td/telegram/FullMessageId.h"
 #include "td/telegram/logevent/LogEvent.h"
+#include "td/telegram/MessageContentType.h"
 #include "td/telegram/MessageEntity.h"
 #include "td/telegram/MessageId.h"
 #include "td/telegram/Photo.h"
@@ -29,7 +30,6 @@
 #include "td/utils/buffer.h"
 #include "td/utils/common.h"
 #include "td/utils/Status.h"
-#include "td/utils/StringBuilder.h"
 
 #include <utility>
 
@@ -41,53 +41,6 @@ class Td;
 
 class MultiPromiseActor;
 
-enum class MessageContentType : int32 {
-  None = -1,
-  Text,
-  Animation,
-  Audio,
-  Document,
-  Photo,
-  Sticker,
-  Video,
-  VoiceNote,
-  Contact,
-  Location,
-  Venue,
-  ChatCreate,
-  ChatChangeTitle,
-  ChatChangePhoto,
-  ChatDeletePhoto,
-  ChatDeleteHistory,
-  ChatAddUsers,
-  ChatJoinedByLink,
-  ChatDeleteUser,
-  ChatMigrateTo,
-  ChannelCreate,
-  ChannelMigrateFrom,
-  PinMessage,
-  Game,
-  GameScore,
-  ScreenshotTaken,
-  ChatSetTtl,
-  Unsupported,
-  Call,
-  Invoice,
-  PaymentSuccessful,
-  VideoNote,
-  ContactRegistered,
-  ExpiredPhoto,
-  ExpiredVideo,
-  LiveLocation,
-  CustomServiceAction,
-  WebsiteConnected,
-  PassportDataSent,
-  PassportDataReceived,
-  Poll
-};
-
-StringBuilder &operator<<(StringBuilder &string_builder, MessageContentType content_type);
-
 // Do not forget to update merge_message_contents when one of the inheritors of this class changes
 class MessageContent {
  public:
@@ -162,16 +115,8 @@ tl_object_ptr<telegram_api::InputMedia> get_input_media(const MessageContent *co
 
 void delete_message_content_thumbnail(MessageContent *content, Td *td);
 
-bool is_allowed_media_group_content(MessageContentType content_type);
-
 bool can_forward_message_content(const MessageContent *content);
 
-bool is_secret_message_content(int32 ttl, MessageContentType content_type);
-
-bool is_service_message_content(MessageContentType content_type);
-
-bool can_have_message_content_caption(MessageContentType content_type);
-
 bool update_opened_message_content(MessageContent *content);
 
 int32 get_message_content_index_mask(const MessageContent *content, const Td *td, bool is_secret, bool is_outgoing);
diff --git a/td/telegram/MessageContentType.cpp b/td/telegram/MessageContentType.cpp
new file mode 100644
index 00000000..8d58addb
--- /dev/null
+++ b/td/telegram/MessageContentType.cpp
@@ -0,0 +1,310 @@
+//
+// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2020
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+#include "td/telegram/MessageContentType.h"
+
+namespace td {
+
+StringBuilder &operator<<(StringBuilder &string_builder, MessageContentType content_type) {
+  switch (content_type) {
+    case MessageContentType::None:
+      return string_builder << "None";
+    case MessageContentType::Animation:
+      return string_builder << "Animation";
+    case MessageContentType::Audio:
+      return string_builder << "Audio";
+    case MessageContentType::Document:
+      return string_builder << "Document";
+    case MessageContentType::ExpiredPhoto:
+      return string_builder << "ExpiredPhoto";
+    case MessageContentType::Photo:
+      return string_builder << "Photo";
+    case MessageContentType::ExpiredVideo:
+      return string_builder << "ExpiredVideo";
+    case MessageContentType::Video:
+      return string_builder << "Video";
+    case MessageContentType::VideoNote:
+      return string_builder << "VideoNote";
+    case MessageContentType::VoiceNote:
+      return string_builder << "VoiceNote";
+    case MessageContentType::Contact:
+      return string_builder << "Contact";
+    case MessageContentType::LiveLocation:
+      return string_builder << "LiveLocation";
+    case MessageContentType::Location:
+      return string_builder << "Location";
+    case MessageContentType::Venue:
+      return string_builder << "Venue";
+    case MessageContentType::Game:
+      return string_builder << "Game";
+    case MessageContentType::Invoice:
+      return string_builder << "Invoice";
+    case MessageContentType::Sticker:
+      return string_builder << "Sticker";
+    case MessageContentType::Text:
+      return string_builder << "Text";
+    case MessageContentType::Unsupported:
+      return string_builder << "Unsupported";
+    case MessageContentType::ChatCreate:
+      return string_builder << "ChatCreate";
+    case MessageContentType::ChatChangeTitle:
+      return string_builder << "ChatChangeTitle";
+    case MessageContentType::ChatChangePhoto:
+      return string_builder << "ChatChangePhoto";
+    case MessageContentType::ChatDeletePhoto:
+      return string_builder << "ChatDeletePhoto";
+    case MessageContentType::ChatDeleteHistory:
+      return string_builder << "ChatDeleteHistory";
+    case MessageContentType::ChatAddUsers:
+      return string_builder << "ChatAddUsers";
+    case MessageContentType::ChatJoinedByLink:
+      return string_builder << "ChatJoinedByLink";
+    case MessageContentType::ChatDeleteUser:
+      return string_builder << "ChatDeleteUser";
+    case MessageContentType::ChatMigrateTo:
+      return string_builder << "ChatMigrateTo";
+    case MessageContentType::ChannelCreate:
+      return string_builder << "ChannelCreate";
+    case MessageContentType::ChannelMigrateFrom:
+      return string_builder << "ChannelMigrateFrom";
+    case MessageContentType::PinMessage:
+      return string_builder << "PinMessage";
+    case MessageContentType::GameScore:
+      return string_builder << "GameScore";
+    case MessageContentType::ScreenshotTaken:
+      return string_builder << "ScreenshotTaken";
+    case MessageContentType::ChatSetTtl:
+      return string_builder << "ChatSetTtl";
+    case MessageContentType::Call:
+      return string_builder << "Call";
+    case MessageContentType::PaymentSuccessful:
+      return string_builder << "PaymentSuccessful";
+    case MessageContentType::ContactRegistered:
+      return string_builder << "ContactRegistered";
+    case MessageContentType::CustomServiceAction:
+      return string_builder << "CustomServiceAction";
+    case MessageContentType::WebsiteConnected:
+      return string_builder << "WebsiteConnected";
+    case MessageContentType::PassportDataSent:
+      return string_builder << "PassportDataSent";
+    case MessageContentType::PassportDataReceived:
+      return string_builder << "PassportDataReceived";
+    case MessageContentType::Poll:
+      return string_builder << "Poll";
+    default:
+      UNREACHABLE();
+      return string_builder;
+  }
+}
+
+bool is_allowed_media_group_content(MessageContentType content_type) {
+  switch (content_type) {
+    case MessageContentType::Photo:
+    case MessageContentType::Video:
+    case MessageContentType::ExpiredPhoto:
+    case MessageContentType::ExpiredVideo:
+      return true;
+    case MessageContentType::Animation:
+    case MessageContentType::Audio:
+    case MessageContentType::Contact:
+    case MessageContentType::Document:
+    case MessageContentType::Game:
+    case MessageContentType::Invoice:
+    case MessageContentType::LiveLocation:
+    case MessageContentType::Location:
+    case MessageContentType::Sticker:
+    case MessageContentType::Text:
+    case MessageContentType::Unsupported:
+    case MessageContentType::Venue:
+    case MessageContentType::VideoNote:
+    case MessageContentType::VoiceNote:
+    case MessageContentType::ChatCreate:
+    case MessageContentType::ChatChangeTitle:
+    case MessageContentType::ChatChangePhoto:
+    case MessageContentType::ChatDeletePhoto:
+    case MessageContentType::ChatDeleteHistory:
+    case MessageContentType::ChatAddUsers:
+    case MessageContentType::ChatJoinedByLink:
+    case MessageContentType::ChatDeleteUser:
+    case MessageContentType::ChatMigrateTo:
+    case MessageContentType::ChannelCreate:
+    case MessageContentType::ChannelMigrateFrom:
+    case MessageContentType::PinMessage:
+    case MessageContentType::GameScore:
+    case MessageContentType::ScreenshotTaken:
+    case MessageContentType::ChatSetTtl:
+    case MessageContentType::Call:
+    case MessageContentType::PaymentSuccessful:
+    case MessageContentType::ContactRegistered:
+    case MessageContentType::CustomServiceAction:
+    case MessageContentType::WebsiteConnected:
+    case MessageContentType::PassportDataSent:
+    case MessageContentType::PassportDataReceived:
+    case MessageContentType::Poll:
+      return false;
+    default:
+      UNREACHABLE();
+      return false;
+  }
+}
+
+bool is_secret_message_content(int32 ttl, MessageContentType content_type) {
+  if (ttl <= 0 || ttl > 60) {
+    return false;
+  }
+  switch (content_type) {
+    case MessageContentType::Animation:
+    case MessageContentType::Audio:
+    case MessageContentType::Photo:
+    case MessageContentType::Video:
+    case MessageContentType::VideoNote:
+    case MessageContentType::VoiceNote:
+      return true;
+    case MessageContentType::Contact:
+    case MessageContentType::Document:
+    case MessageContentType::Game:
+    case MessageContentType::Invoice:
+    case MessageContentType::LiveLocation:
+    case MessageContentType::Location:
+    case MessageContentType::Sticker:
+    case MessageContentType::Text:
+    case MessageContentType::Unsupported:
+    case MessageContentType::Venue:
+    case MessageContentType::ExpiredPhoto:
+    case MessageContentType::ExpiredVideo:
+    case MessageContentType::ChatCreate:
+    case MessageContentType::ChatChangeTitle:
+    case MessageContentType::ChatChangePhoto:
+    case MessageContentType::ChatDeletePhoto:
+    case MessageContentType::ChatDeleteHistory:
+    case MessageContentType::ChatAddUsers:
+    case MessageContentType::ChatJoinedByLink:
+    case MessageContentType::ChatDeleteUser:
+    case MessageContentType::ChatMigrateTo:
+    case MessageContentType::ChannelCreate:
+    case MessageContentType::ChannelMigrateFrom:
+    case MessageContentType::PinMessage:
+    case MessageContentType::GameScore:
+    case MessageContentType::ScreenshotTaken:
+    case MessageContentType::ChatSetTtl:
+    case MessageContentType::Call:
+    case MessageContentType::PaymentSuccessful:
+    case MessageContentType::ContactRegistered:
+    case MessageContentType::CustomServiceAction:
+    case MessageContentType::WebsiteConnected:
+    case MessageContentType::PassportDataSent:
+    case MessageContentType::PassportDataReceived:
+    case MessageContentType::Poll:
+      return false;
+    default:
+      UNREACHABLE();
+      return false;
+  }
+}
+
+bool is_service_message_content(MessageContentType content_type) {
+  switch (content_type) {
+    case MessageContentType::Animation:
+    case MessageContentType::Audio:
+    case MessageContentType::Contact:
+    case MessageContentType::Document:
+    case MessageContentType::Game:
+    case MessageContentType::Invoice:
+    case MessageContentType::LiveLocation:
+    case MessageContentType::Location:
+    case MessageContentType::Photo:
+    case MessageContentType::Sticker:
+    case MessageContentType::Text:
+    case MessageContentType::Unsupported:
+    case MessageContentType::Venue:
+    case MessageContentType::Video:
+    case MessageContentType::VideoNote:
+    case MessageContentType::VoiceNote:
+    case MessageContentType::ExpiredPhoto:
+    case MessageContentType::ExpiredVideo:
+    case MessageContentType::Poll:
+      return false;
+    case MessageContentType::ChatCreate:
+    case MessageContentType::ChatChangeTitle:
+    case MessageContentType::ChatChangePhoto:
+    case MessageContentType::ChatDeletePhoto:
+    case MessageContentType::ChatDeleteHistory:
+    case MessageContentType::ChatAddUsers:
+    case MessageContentType::ChatJoinedByLink:
+    case MessageContentType::ChatDeleteUser:
+    case MessageContentType::ChatMigrateTo:
+    case MessageContentType::ChannelCreate:
+    case MessageContentType::ChannelMigrateFrom:
+    case MessageContentType::PinMessage:
+    case MessageContentType::GameScore:
+    case MessageContentType::ScreenshotTaken:
+    case MessageContentType::ChatSetTtl:
+    case MessageContentType::Call:
+    case MessageContentType::PaymentSuccessful:
+    case MessageContentType::ContactRegistered:
+    case MessageContentType::CustomServiceAction:
+    case MessageContentType::WebsiteConnected:
+    case MessageContentType::PassportDataSent:
+    case MessageContentType::PassportDataReceived:
+      return true;
+    default:
+      UNREACHABLE();
+      return false;
+  }
+}
+
+bool can_have_message_content_caption(MessageContentType content_type) {
+  switch (content_type) {
+    case MessageContentType::Animation:
+    case MessageContentType::Audio:
+    case MessageContentType::Document:
+    case MessageContentType::Photo:
+    case MessageContentType::Video:
+    case MessageContentType::VoiceNote:
+      return true;
+    case MessageContentType::Contact:
+    case MessageContentType::Game:
+    case MessageContentType::Invoice:
+    case MessageContentType::LiveLocation:
+    case MessageContentType::Location:
+    case MessageContentType::Sticker:
+    case MessageContentType::Text:
+    case MessageContentType::Unsupported:
+    case MessageContentType::Venue:
+    case MessageContentType::VideoNote:
+    case MessageContentType::ChatCreate:
+    case MessageContentType::ChatChangeTitle:
+    case MessageContentType::ChatChangePhoto:
+    case MessageContentType::ChatDeletePhoto:
+    case MessageContentType::ChatDeleteHistory:
+    case MessageContentType::ChatAddUsers:
+    case MessageContentType::ChatJoinedByLink:
+    case MessageContentType::ChatDeleteUser:
+    case MessageContentType::ChatMigrateTo:
+    case MessageContentType::ChannelCreate:
+    case MessageContentType::ChannelMigrateFrom:
+    case MessageContentType::PinMessage:
+    case MessageContentType::GameScore:
+    case MessageContentType::ScreenshotTaken:
+    case MessageContentType::ChatSetTtl:
+    case MessageContentType::Call:
+    case MessageContentType::PaymentSuccessful:
+    case MessageContentType::ContactRegistered:
+    case MessageContentType::ExpiredPhoto:
+    case MessageContentType::ExpiredVideo:
+    case MessageContentType::CustomServiceAction:
+    case MessageContentType::WebsiteConnected:
+    case MessageContentType::PassportDataSent:
+    case MessageContentType::PassportDataReceived:
+    case MessageContentType::Poll:
+      return false;
+    default:
+      UNREACHABLE();
+      return false;
+  }
+}
+
+}  // namespace td
diff --git a/td/telegram/MessageContentType.h b/td/telegram/MessageContentType.h
new file mode 100644
index 00000000..240b58b9
--- /dev/null
+++ b/td/telegram/MessageContentType.h
@@ -0,0 +1,69 @@
+//
+// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2020
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+#pragma once
+
+#include "td/utils/common.h"
+#include "td/utils/StringBuilder.h"
+
+namespace td {
+
+enum class MessageContentType : int32 {
+  None = -1,
+  Text,
+  Animation,
+  Audio,
+  Document,
+  Photo,
+  Sticker,
+  Video,
+  VoiceNote,
+  Contact,
+  Location,
+  Venue,
+  ChatCreate,
+  ChatChangeTitle,
+  ChatChangePhoto,
+  ChatDeletePhoto,
+  ChatDeleteHistory,
+  ChatAddUsers,
+  ChatJoinedByLink,
+  ChatDeleteUser,
+  ChatMigrateTo,
+  ChannelCreate,
+  ChannelMigrateFrom,
+  PinMessage,
+  Game,
+  GameScore,
+  ScreenshotTaken,
+  ChatSetTtl,
+  Unsupported,
+  Call,
+  Invoice,
+  PaymentSuccessful,
+  VideoNote,
+  ContactRegistered,
+  ExpiredPhoto,
+  ExpiredVideo,
+  LiveLocation,
+  CustomServiceAction,
+  WebsiteConnected,
+  PassportDataSent,
+  PassportDataReceived,
+  Poll
+};
+
+StringBuilder &operator<<(StringBuilder &string_builder, MessageContentType content_type);
+
+bool is_allowed_media_group_content(MessageContentType content_type);
+
+bool is_secret_message_content(int32 ttl, MessageContentType content_type);
+
+bool is_service_message_content(MessageContentType content_type);
+
+bool can_have_message_content_caption(MessageContentType content_type);
+
+}  // namespace td
diff --git a/td/telegram/MessagesManager.h b/td/telegram/MessagesManager.h
index 3220080c..64953ea4 100644
--- a/td/telegram/MessagesManager.h
+++ b/td/telegram/MessagesManager.h
@@ -25,6 +25,7 @@
 #include "td/telegram/FullMessageId.h"
 #include "td/telegram/Global.h"
 #include "td/telegram/MessageContent.h"
+#include "td/telegram/MessageContentType.h"
 #include "td/telegram/MessageEntity.h"
 #include "td/telegram/MessageId.h"
 #include "td/telegram/MessagesDb.h"