diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1027f8d9a..aaef3c5a2 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -561,6 +561,8 @@ set(APP_HEADERS
   # TT-RSS service headers.
   src/services/tt-rss/ttrssserviceroot.h
   src/services/tt-rss/ttrssrecyclebin.h
+  src/services/tt-rss/ttrssfeed.h
+  src/services/tt-rss/ttrsscategory.h
   src/services/tt-rss/gui/formeditaccount.h
 
   # NETWORK-WEB headers.
diff --git a/src/services/tt-rss/ttrsscategory.h b/src/services/tt-rss/ttrsscategory.h
index c029d3435..54e573448 100755
--- a/src/services/tt-rss/ttrsscategory.h
+++ b/src/services/tt-rss/ttrsscategory.h
@@ -24,11 +24,15 @@
 
 
 class TtRssCategory : public Category {
+    Q_OBJECT
+
   public:
     explicit TtRssCategory(RootItem *parent = NULL);
     explicit TtRssCategory(const QSqlRecord &record);
     virtual ~TtRssCategory();
 
+
+
     int customId() const;
     void setCustomId(int custom_id);
 
diff --git a/src/services/tt-rss/ttrssfeed.h b/src/services/tt-rss/ttrssfeed.h
index 87a2c3e9f..ccd78d386 100755
--- a/src/services/tt-rss/ttrssfeed.h
+++ b/src/services/tt-rss/ttrssfeed.h
@@ -26,6 +26,8 @@
 class TtRssServiceRoot;
 
 class TtRssFeed : public Feed {
+    Q_OBJECT
+
   public:
     explicit TtRssFeed(RootItem *parent = NULL);
     explicit TtRssFeed(const QSqlRecord &record);
diff --git a/src/services/tt-rss/ttrssserviceroot.cpp b/src/services/tt-rss/ttrssserviceroot.cpp
index ea9f22036..ca6061a64 100755
--- a/src/services/tt-rss/ttrssserviceroot.cpp
+++ b/src/services/tt-rss/ttrssserviceroot.cpp
@@ -222,6 +222,77 @@ TtRssNetworkFactory *TtRssServiceRoot::network() const {
   return m_network;
 }
 
+QStringList TtRssServiceRoot::customIDSOfMessagesForItem(RootItem *item) {
+  if (item->getParentServiceRoot() != this) {
+    // Not item from this account.
+    return QStringList();
+  }
+  else {
+    QStringList list;
+
+    switch (item->kind()) {
+      case RootItemKind::Category: {
+        foreach (RootItem *child, item->childItems()) {
+          list.append(customIDSOfMessagesForItem(child));
+        }
+
+        return list;
+      }
+
+      case RootItemKind::ServiceRoot: {
+        QSqlDatabase database = qApp->database()->connection(metaObject()->className(), DatabaseFactory::FromSettings);
+        QSqlQuery query(database);
+
+        query.prepare(QSL("SELECT custom_id FROM Messages WHERE is_deleted = 0 AND is_pdeleted = 0 AND account_id = :account_id;"));
+        query.bindValue(QSL(":account_id"), accountId());
+        query.exec();
+
+        while (query.next()) {
+          list.append(query.value(0).toString());
+        }
+
+        break;
+      }
+
+      case RootItemKind::Bin: {
+        QSqlDatabase database = qApp->database()->connection(metaObject()->className(), DatabaseFactory::FromSettings);
+        QSqlQuery query(database);
+
+        query.prepare(QSL("SELECT custom_id FROM Messages WHERE is_deleted = 1 AND is_pdeleted = 0 AND account_id = :account_id;"));
+        query.bindValue(QSL(":account_id"), accountId());
+        query.exec();
+
+        while (query.next()) {
+          list.append(query.value(0).toString());
+        }
+
+        break;
+      }
+
+      case RootItemKind::Feed: {
+        QSqlDatabase database = qApp->database()->connection(metaObject()->className(), DatabaseFactory::FromSettings);
+        QSqlQuery query(database);
+
+        query.prepare(QSL("SELECT custom_id FROM Messages WHERE is_deleted = 0 AND is_pdeleted = 0 AND feed = :feed AND account_id = :account_id;"));
+        query.bindValue(QSL(":account_id"), accountId());
+        query.bindValue(QSL(":feed"), qobject_cast<TtRssFeed*>(item)->customId());
+        query.exec();
+
+        while (query.next()) {
+          list.append(query.value(0).toString());
+        }
+
+        break;
+      }
+
+      default:
+        break;
+    }
+
+    return list;
+  }
+}
+
 void TtRssServiceRoot::saveAccountDataToDatabase() {
   if (accountId() != NO_PARENT_CATEGORY) {
     // We are overwritting previously saved data.
diff --git a/src/services/tt-rss/ttrssserviceroot.h b/src/services/tt-rss/ttrssserviceroot.h
index 903100cb9..6f594ab7f 100755
--- a/src/services/tt-rss/ttrssserviceroot.h
+++ b/src/services/tt-rss/ttrssserviceroot.h
@@ -68,9 +68,11 @@ class TtRssServiceRoot : public ServiceRoot {
 
     TtRssNetworkFactory *network() const;
 
+    // Returns list of custom IDS of all DB messages in given item.
+    QStringList customIDSOfMessagesForItem(RootItem *item);
+
     void saveAccountDataToDatabase();
     void updateTitle();
-
     void completelyRemoveAllData();
 
   public slots: