diff --git a/td/telegram/ContactsManager.cpp b/td/telegram/ContactsManager.cpp
index e01e3fed5..7ba482b35 100644
--- a/td/telegram/ContactsManager.cpp
+++ b/td/telegram/ContactsManager.cpp
@@ -11549,7 +11549,7 @@ UserId ContactsManager::get_me(Promise<Unit> &&promise) {
 
 bool ContactsManager::get_user(UserId user_id, int left_tries, Promise<Unit> &&promise) {
   if (!user_id.is_valid()) {
-    promise.set_error(Status::Error(6, "Invalid user ID"));
+    promise.set_error(Status::Error(6, "Invalid user identifier"));
     return false;
   }
 
@@ -11620,7 +11620,7 @@ ContactsManager::UserFull *ContactsManager::add_user_full(UserId user_id) {
 
 void ContactsManager::reload_user(UserId user_id, Promise<Unit> &&promise) {
   if (!user_id.is_valid()) {
-    return promise.set_error(Status::Error(6, "Invalid user ID"));
+    return promise.set_error(Status::Error(6, "Invalid user identifier"));
   }
 
   have_user_force(user_id);
@@ -11854,7 +11854,7 @@ ContactsManager::Chat *ContactsManager::add_chat(ChatId chat_id) {
 
 bool ContactsManager::get_chat(ChatId chat_id, int left_tries, Promise<Unit> &&promise) {
   if (!chat_id.is_valid()) {
-    promise.set_error(Status::Error(6, "Invalid basic group ID"));
+    promise.set_error(Status::Error(6, "Invalid basic group identifier"));
     return false;
   }
 
@@ -11880,7 +11880,7 @@ bool ContactsManager::get_chat(ChatId chat_id, int left_tries, Promise<Unit> &&p
 
 void ContactsManager::reload_chat(ChatId chat_id, Promise<Unit> &&promise) {
   if (!chat_id.is_valid()) {
-    return promise.set_error(Status::Error(6, "Invalid basic group ID"));
+    return promise.set_error(Status::Error(6, "Invalid basic group identifier"));
   }
 
   // there is no much reason to combine different requests into one request
@@ -12173,7 +12173,7 @@ ContactsManager::Channel *ContactsManager::add_channel(ChannelId channel_id, con
 
 bool ContactsManager::get_channel(ChannelId channel_id, int left_tries, Promise<Unit> &&promise) {
   if (!channel_id.is_valid()) {
-    promise.set_error(Status::Error(6, "Invalid supergroup ID"));
+    promise.set_error(Status::Error(6, "Invalid supergroup identifier"));
     return false;
   }
 
@@ -12199,7 +12199,7 @@ bool ContactsManager::get_channel(ChannelId channel_id, int left_tries, Promise<
 
 void ContactsManager::reload_channel(ChannelId channel_id, Promise<Unit> &&promise) {
   if (!channel_id.is_valid()) {
-    return promise.set_error(Status::Error(6, "Invalid supergroup ID"));
+    return promise.set_error(Status::Error(6, "Invalid supergroup identifier"));
   }
 
   have_channel_force(channel_id);
@@ -12332,7 +12332,7 @@ ContactsManager::SecretChat *ContactsManager::get_secret_chat(SecretChatId secre
 
 bool ContactsManager::get_secret_chat(SecretChatId secret_chat_id, bool force, Promise<Unit> &&promise) {
   if (!secret_chat_id.is_valid()) {
-    promise.set_error(Status::Error(6, "Invalid secret chat ID"));
+    promise.set_error(Status::Error(6, "Invalid secret chat identifier"));
     return false;
   }
 
diff --git a/td/telegram/MessagesManager.cpp b/td/telegram/MessagesManager.cpp
index cc0e9bf60..3eaa1397e 100644
--- a/td/telegram/MessagesManager.cpp
+++ b/td/telegram/MessagesManager.cpp
@@ -8809,7 +8809,7 @@ void MessagesManager::delete_dialog_history(DialogId dialog_id, bool remove_from
 
   auto last_new_message_id = d->last_new_message_id;
   if (dialog_type != DialogType::SecretChat && last_new_message_id == MessageId()) {
-    // TODO get dialog from the server and delete history from last message id
+    // TODO get dialog from the server and delete history from last message identifier
   }
 
   bool allow_error = d->messages == nullptr;
@@ -26015,7 +26015,7 @@ MessagesManager::Message *MessagesManager::add_message_to_dialog(DialogId dialog
   MessageId message_id = message->message_id;
   if (!message_id.is_valid() && !message_id.is_valid_scheduled()) {
     LOG(ERROR) << "Receive " << message_id << " in " << dialog_id << " from " << source;
-    debug_add_message_to_dialog_fail_reason_ = "invalid message id";
+    debug_add_message_to_dialog_fail_reason_ = "invalid message identifier";
     return nullptr;
   }
 
@@ -26068,7 +26068,7 @@ MessagesManager::Message *MessagesManager::add_message_to_dialog(Dialog *d, uniq
     }
     LOG(ERROR) << "Receive " << message_id << " in " << dialog_id << " from " << source;
     CHECK(!message->from_database);
-    debug_add_message_to_dialog_fail_reason_ = "invalid message id";
+    debug_add_message_to_dialog_fail_reason_ = "invalid message identifier";
     return nullptr;
   }
 
@@ -27922,7 +27922,7 @@ void MessagesManager::fix_new_dialog(Dialog *d, unique_ptr<Message> &&last_datab
       VLOG(notifications) << "Fix removing new secret chat " << d->new_secret_chat_notification_id << " in "
                           << dialog_id;
       d->new_secret_chat_notification_id = NotificationId();
-      on_dialog_updated(dialog_id, "fix new secret chat notification id");
+      on_dialog_updated(dialog_id, "fix new secret chat notification identifier");
     }
   }
 
diff --git a/td/telegram/PhotoSizeSource.hpp b/td/telegram/PhotoSizeSource.hpp
index 81fd5fcfb..7cadf4c19 100644
--- a/td/telegram/PhotoSizeSource.hpp
+++ b/td/telegram/PhotoSizeSource.hpp
@@ -69,7 +69,7 @@ void parse(PhotoSizeSource::DialogPhoto &source, ParserT &parser) {
   switch (source.dialog_id.get_type()) {
     case DialogType::SecretChat:
     case DialogType::None:
-      return parser.set_error("Invalid chat id");
+      return parser.set_error("Invalid chat identifier");
     default:
       break;
   }
diff --git a/td/telegram/Td.cpp b/td/telegram/Td.cpp
index db86769e8..1537614d7 100644
--- a/td/telegram/Td.cpp
+++ b/td/telegram/Td.cpp
@@ -5032,7 +5032,7 @@ void Td::on_request(uint64 id, td_api::optimizeStorage &request) {
   for (auto chat_id : request.chat_ids_) {
     DialogId dialog_id(chat_id);
     if (!dialog_id.is_valid() && dialog_id != DialogId()) {
-      return send_error_raw(id, 400, "Wrong chat id");
+      return send_error_raw(id, 400, "Wrong chat identifier");
     }
     owner_dialog_ids.push_back(dialog_id);
   }
@@ -5040,7 +5040,7 @@ void Td::on_request(uint64 id, td_api::optimizeStorage &request) {
   for (auto chat_id : request.exclude_chat_ids_) {
     DialogId dialog_id(chat_id);
     if (!dialog_id.is_valid() && dialog_id != DialogId()) {
-      return send_error_raw(id, 400, "Wrong chat id");
+      return send_error_raw(id, 400, "Wrong chat identifier");
     }
     exclude_owner_dialog_ids.push_back(dialog_id);
   }
@@ -5958,7 +5958,7 @@ void Td::on_request(uint64 id, const td_api::downloadFile &request) {
   FileId file_id(request.file_id_, 0);
   auto file_view = file_manager_->get_file_view(file_id);
   if (file_view.empty()) {
-    return send_error_raw(id, 400, "Invalid file id");
+    return send_error_raw(id, 400, "Invalid file identifier");
   }
 
   auto info_it = pending_file_downloads_.find(file_id);
diff --git a/td/telegram/files/FileManager.cpp b/td/telegram/files/FileManager.cpp
index d3476e447..d65279b25 100644
--- a/td/telegram/files/FileManager.cpp
+++ b/td/telegram/files/FileManager.cpp
@@ -1944,7 +1944,7 @@ void FileManager::read_file_part(FileId file_id, int32 offset, int32 count, int
   }
 
   if (!file_id.is_valid()) {
-    return promise.set_error(Status::Error(400, "File ID is invalid"));
+    return promise.set_error(Status::Error(400, "File identifier is invalid"));
   }
   auto node = get_sync_file_node(file_id);
   if (!node) {
@@ -2446,7 +2446,7 @@ void FileManager::resume_upload(FileId file_id, std::vector<int> bad_parts, std:
 bool FileManager::delete_partial_remote_location(FileId file_id) {
   auto node = get_sync_file_node(file_id);
   if (!node) {
-    LOG(INFO) << "Wrong file id " << file_id;
+    LOG(INFO) << "Wrong file identifier " << file_id;
     return false;
   }
   if (node->upload_pause_ == file_id) {
@@ -2482,7 +2482,7 @@ void FileManager::delete_file_reference(FileId file_id, string file_reference) {
                         << tag("reference_base64", base64_encode(file_reference));
   auto node = get_sync_file_node(file_id);
   if (!node) {
-    LOG(ERROR) << "Wrong file id " << file_id;
+    LOG(ERROR) << "Wrong file identifier " << file_id;
     return;
   }
   node->delete_file_reference(file_reference);
@@ -2765,11 +2765,11 @@ Result<FileId> FileManager::from_persistent_id(CSlice persistent_id, FileType fi
 
   auto r_binary = base64url_decode(persistent_id);
   if (r_binary.is_error()) {
-    return Status::Error(10, PSLICE() << "Wrong remote file id specified: " << r_binary.error().message());
+    return Status::Error(10, PSLICE() << "Wrong remote file identifier specified: " << r_binary.error().message());
   }
   auto binary = r_binary.move_as_ok();
   if (binary.empty()) {
-    return Status::Error(10, "Remote file id can't be empty");
+    return Status::Error(10, "Remote file identifier can't be empty");
   }
   if (binary.back() == PERSISTENT_ID_VERSION_OLD) {
     return from_persistent_id_v2(binary, file_type);
@@ -2780,7 +2780,7 @@ Result<FileId> FileManager::from_persistent_id(CSlice persistent_id, FileType fi
   if (binary.back() == PERSISTENT_ID_VERSION_MAP) {
     return from_persistent_id_map(binary, file_type);
   }
-  return Status::Error(10, "Wrong remote file id specified: can't unserialize it. Wrong last symbol");
+  return Status::Error(10, "Wrong remote file identifier specified: can't unserialize it. Wrong last symbol");
 }
 
 Result<FileId> FileManager::from_persistent_id_map(Slice binary, FileType file_type) {
@@ -2789,7 +2789,7 @@ Result<FileId> FileManager::from_persistent_id_map(Slice binary, FileType file_t
   FullGenerateFileLocation generate_location;
   auto status = unserialize(generate_location, decoded_binary);
   if (status.is_error()) {
-    return Status::Error(10, "Wrong remote file id specified: can't unserialize it");
+    return Status::Error(10, "Wrong remote file identifier specified: can't unserialize it");
   }
   auto real_file_type = generate_location.file_type_;
   if ((real_file_type != file_type && file_type != FileType::Temp) ||
@@ -2806,7 +2806,7 @@ Result<FileId> FileManager::from_persistent_id_map(Slice binary, FileType file_t
 
 Result<FileId> FileManager::from_persistent_id_v23(Slice binary, FileType file_type, int32 version) {
   if (version < 0 || version >= static_cast<int32>(Version::Next)) {
-    return Status::Error("Invalid remote id");
+    return Status::Error("Invalid remote file identifier");
   }
   auto decoded_binary = zero_decode(binary);
   FullRemoteFileLocation remote_location;
@@ -2816,7 +2816,7 @@ Result<FileId> FileManager::from_persistent_id_v23(Slice binary, FileType file_t
   parser.fetch_end();
   auto status = parser.get_status();
   if (status.is_error()) {
-    return Status::Error(10, "Wrong remote file id specified: can't unserialize it");
+    return Status::Error(10, "Wrong remote file identifier specified: can't unserialize it");
   }
   auto &real_file_type = remote_location.file_type_;
   if (is_document_type(real_file_type) && is_document_type(file_type)) {
@@ -2841,7 +2841,7 @@ Result<FileId> FileManager::from_persistent_id_v2(Slice binary, FileType file_ty
 Result<FileId> FileManager::from_persistent_id_v3(Slice binary, FileType file_type) {
   binary.remove_suffix(1);
   if (binary.empty()) {
-    return Status::Error("Invalid remote id");
+    return Status::Error("Invalid remote file identifier");
   }
   int32 version = static_cast<uint8>(binary.back());
   binary.remove_suffix(1);
diff --git a/td/telegram/net/NetQueryDispatcher.cpp b/td/telegram/net/NetQueryDispatcher.cpp
index 957bbf0aa..28ffd0352 100644
--- a/td/telegram/net/NetQueryDispatcher.cpp
+++ b/td/telegram/net/NetQueryDispatcher.cpp
@@ -122,7 +122,7 @@ Status NetQueryDispatcher::wait_dc_init(DcId dc_id, bool force) {
   }
   size_t pos = static_cast<size_t>(dc_id.get_raw_id() - 1);
   if (pos >= dcs_.size()) {
-    return Status::Error("Too big DC id");
+    return Status::Error("Too big DC ID");
   }
   auto &dc = dcs_[pos];
 
diff --git a/td/telegram/net/Session.cpp b/td/telegram/net/Session.cpp
index edf9c0ea9..9bda51c16 100644
--- a/td/telegram/net/Session.cpp
+++ b/td/telegram/net/Session.cpp
@@ -839,7 +839,7 @@ void Session::on_message_info(uint64 id, int32 state, uint64 answer_id, int32 an
       case 2:
       case 3:
         // message not received by server
-        return on_message_failed(id, Status::Error("Unknown message id"));
+        return on_message_failed(id, Status::Error("Unknown message identifier"));
       case 0:
         if (answer_id == 0) {
           LOG(ERROR) << "Unexpected message_info.state == 0 " << tag("id", id) << tag("state", state)