diff --git a/akonadi/CMakeLists.txt b/akonadi/CMakeLists.txt
index 5025aa9be..08b000242 100644
--- a/akonadi/CMakeLists.txt
+++ b/akonadi/CMakeLists.txt
@@ -1,258 +1,260 @@
 project(akonadi-kde)
 
 add_definitions( -DKDE_DEFAULT_DEBUG_AREA=5250 )
 
 set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${KDE4_ENABLE_EXCEPTIONS}" )
 if(CMAKE_COMPILE_GCOV)
   set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fprofile-arcs -ftest-coverage")
 endif(CMAKE_COMPILE_GCOV)
 
 if (KDE4_BUILD_TESTS)
    # only with this macro the AKONADI_TESTS_EXPORT macro will do something
    add_definitions(-DCOMPILING_TESTS)
 add_subdirectory( tests )
 endif (KDE4_BUILD_TESTS)
 
 add_definitions( -DQT_NO_CAST_FROM_ASCII )
 add_definitions( -DQT_NO_CAST_TO_ASCII )
 
 add_subdirectory( kabc )
 add_subdirectory( kmime )
 
 include_directories(
   ${CMAKE_CURRENT_SOURCE_DIR}
   ${CMAKE_CURRENT_BINARY_DIR}
   ${QT_QTDBUS_INCLUDE_DIR}
   ${Boost_INCLUDE_DIR}
   ${KDE4_INCLUDE_DIR}
   ${AKONADI_INCLUDE_DIR}
   ${AKONADI_INCLUDE_DIR}/akonadi/private
 )
 
 # libakonadi-kde
 
 set( akonadikde_LIB_SRC
   entity.cpp # keep it at top to not break enable-final
   agentbase.cpp
   agentfilterproxymodel.cpp
   agentinstance.cpp
   agentinstancecreatejob.cpp
   agentinstancemodel.cpp
   agentinstancewidget.cpp
   agentmanager.cpp
   agenttype.cpp
   agenttypemodel.cpp
   agenttypewidget.cpp
   agenttypedialog.cpp
   attribute.cpp
   attributefactory.cpp
   cachepolicy.cpp
   cachepolicypage.cpp
   changerecorder.cpp
   collection.cpp
   collectioncopyjob.cpp
   collectioncreatejob.cpp
   collectiondeletejob.cpp
   collectiondialog.cpp
   collectionfilterproxymodel.cpp
   collectiongeneralpropertiespage.cpp
   collectionfetchjob.cpp
   collectionfetchscope.cpp
   collectionmodel.cpp
   collectionmodel_p.cpp
   collectionmodifyjob.cpp
   collectionmovejob.cpp
   collectionpathresolver.cpp
   collectionpropertiesdialog.cpp
   collectionpropertiespage.cpp
   collectionrequester.cpp
   collectionrightsattribute.cpp
   collectionselectjob.cpp
   collectionstatistics.cpp
   collectionstatisticsdelegate.cpp
   collectionstatisticsjob.cpp
   collectionstatisticsmodel.cpp
   collectionsync.cpp
   collectionview.cpp
   control.cpp
   descendantsproxymodel.cpp
   entitydisplayattribute.cpp
+  entityhiddenattribute.cpp
   entitytreemodel.cpp
   entitytreemodel_p.cpp
   entityfilterproxymodel.cpp
   entitytreeviewstatesaver.cpp
   erroroverlay.cpp
   exception.cpp
   expungejob.cpp
   favoritecollectionsmodel.cpp
   firstrun.cpp
   flatcollectionproxymodel.cpp
   item.cpp
   itemcreatejob.cpp
   itemcopyjob.cpp
   itemdeletejob.cpp
   itemfetchjob.cpp
   itemfetchscope.cpp
   itemmodel.cpp
   itemmonitor.cpp
   itemmovejob.cpp
   itemserializer.cpp
   itemserializerplugin.cpp
   itemmodifyjob.cpp
   itemsync.cpp
   itemview.cpp
   job.cpp
   linkjob.cpp
   mimetypechecker.cpp
   monitor.cpp
   monitor_p.cpp
   pastehelper.cpp
   preprocessorbase.cpp
   protocolhelper.cpp
   resourcebase.cpp
   resourcescheduler.cpp
   resourceselectjob.cpp
   searchcreatejob.cpp
   selectionproxymodel.cpp
   selftestdialog.cpp
   session.cpp
   servermanager.cpp
   standardactionmanager.cpp
   statisticsproxymodel.cpp
   statisticstooltipproxymodel.cpp
   subscriptionjob.cpp
   subscriptionchangeproxymodel.cpp
   subscriptiondialog.cpp
   subscriptionmodel.cpp
   transactionjobs.cpp
   transactionsequence.cpp
   unlinkjob.cpp
 # Temporary until ported to Qt-plugin framework
   pluginloader.cpp
 )
 
 # DBus interfaces and adaptors
 set(akonadi_xml ${AKONADI_DBUS_INTERFACES_DIR}/org.freedesktop.Akonadi.NotificationManager.xml)
 set_source_files_properties(${akonadi_xml} PROPERTIES INCLUDE "notificationmessage_p.h")
 qt4_add_dbus_interface( akonadikde_LIB_SRC ${akonadi_xml} notificationmanagerinterface )
 qt4_add_dbus_interfaces( akonadikde_LIB_SRC ${AKONADI_DBUS_INTERFACES_DIR}/org.freedesktop.Akonadi.AgentManager.xml )
 qt4_add_dbus_interfaces( akonadikde_LIB_SRC ${AKONADI_DBUS_INTERFACES_DIR}/org.freedesktop.Akonadi.Tracer.xml )
 qt4_add_dbus_adaptor( akonadikde_LIB_SRC ${AKONADI_DBUS_INTERFACES_DIR}/org.freedesktop.Akonadi.Resource.xml resourcebase.h Akonadi::ResourceBase )
 qt4_add_dbus_adaptor( akonadikde_LIB_SRC ${AKONADI_DBUS_INTERFACES_DIR}/org.freedesktop.Akonadi.Preprocessor.xml preprocessorbase.h Akonadi::PreprocessorBase )
 qt4_add_dbus_adaptor( akonadikde_LIB_SRC ${AKONADI_DBUS_INTERFACES_DIR}/org.freedesktop.Akonadi.Agent.Status.xml agentbase.h Akonadi::AgentBase )
 qt4_add_dbus_adaptor( akonadikde_LIB_SRC ${AKONADI_DBUS_INTERFACES_DIR}/org.freedesktop.Akonadi.Agent.Control.xml agentbase.h Akonadi::AgentBase )
 
 kde4_add_ui_files( akonadikde_LIB_SRC
   cachepolicypage.ui
   collectiongeneralpropertiespage.ui
   subscriptiondialog.ui
   controlprogressindicator.ui
   selftestdialog.ui
 )
 
 kde4_add_library( akonadi-kde SHARED ${akonadikde_LIB_SRC} )
 
 macro_ensure_version( "4.2.0" ${KDE_VERSION} KDE_IS_AT_LEAST_42 )
 
 target_link_libraries( akonadi-kde ${KDE4_SOLID_LIBS} ${QT_QTNETWORK_LIBRARY} ${QT_QTDBUS_LIBRARY} ${QT_QTSQL_LIBRARY} ${KDE4_KDEUI_LIBS} ${KDE4_KIO_LIBS} ${AKONADI_COMMON_LIBRARIES} )
 set( AKONADI_KDE_DEPS ${KDE4_KDEUI_LIBS} ${QT_QTDBUS_LIBRARY} ${QT_QTCORE_LIBRARY} )
 
 if(${KDE_IS_AT_LEAST_42})
 target_link_libraries( akonadi-kde LINK_INTERFACE_LIBRARIES ${AKONADI_KDE_DEPS})
 else(${KDE_IS_AT_LEAST_42})
 target_link_libraries( akonadi-kde ${AKONADI_KDE_DEPS})
 endif(${KDE_IS_AT_LEAST_42})
 
 
 set_target_properties( akonadi-kde PROPERTIES VERSION ${GENERIC_LIB_VERSION} SOVERSION ${GENERIC_LIB_SOVERSION} )
 install( TARGETS akonadi-kde EXPORT kdepimlibsLibraryTargets  ${INSTALL_TARGETS_DEFAULT_ARGS} )
 
 ########### install files ###############
 
 install( FILES
   akonadi_export.h
   agentbase.h
   agentfilterproxymodel.h
   agentinstance.h
   agentinstancecreatejob.h
   agentinstancemodel.h
   agentinstancewidget.h
   agentmanager.h
   agenttype.h
   agenttypemodel.h
   agenttypewidget.h
   agenttypedialog.h
   attribute.h
   attributefactory.h
   cachepolicy.h
   changerecorder.h
   collection.h
   collectioncopyjob.h
   collectioncreatejob.h
   collectiondeletejob.h
   collectiondialog.h
   collectionfilterproxymodel.h
   collectionfetchjob.h
   collectionfetchscope.h
   collectionmodel.h
   collectionmodifyjob.h
   collectionpropertiesdialog.h
   collectionpropertiespage.h
   collectionrequester.h
   collectionstatisticsdelegate.h
   collectionstatisticsmodel.h
   collectionstatistics.h
   collectionstatisticsjob.h
   collectionview.h
   control.h
   descendantsproxymodel.h
   entity.h
   entitydisplayattribute.h
+  entityhiddenattribute.h
   entitytreemodel.h
   entityfilterproxymodel.h
   entitytreeviewstatesaver.h
   exception.h
   favoritecollectionsmodel.h
   item.h
   itemcreatejob.h
   itemcopyjob.h
   itemdeletejob.h
   itemfetchjob.h
   itemfetchscope.h
   itemmodel.h
   itemmodifyjob.h
   itemmonitor.h
   itemmovejob.h
   itempayloadinternals_p.h
   itemserializerplugin.h
   itemsync.h
   itemview.h
   job.h
   linkjob.h
   mimetypechecker.h
   monitor.h
   qtest_akonadi.h
   preprocessorbase.h
   resourcebase.h
   searchcreatejob.h
   selectionproxymodel.h
   session.h
   servermanager.h
   standardactionmanager.h
   statisticsproxymodel.h
   statisticstooltipproxymodel.h
   transactionjobs.h
   transactionsequence.h
   unlinkjob.h
   DESTINATION ${INCLUDE_INSTALL_DIR}/akonadi COMPONENT Devel
 )
 
 install( FILES
    collectionpathresolver_p.h
    DESTINATION ${INCLUDE_INSTALL_DIR}/akonadi/private COMPONENT Devel
    )
 
 install( FILES
   kcfg2dbus.xsl
   DESTINATION ${DATA_INSTALL_DIR}/akonadi-kde
 )
diff --git a/akonadi/attributefactory.cpp b/akonadi/attributefactory.cpp
index 4252147bd..c075fa424 100644
--- a/akonadi/attributefactory.cpp
+++ b/akonadi/attributefactory.cpp
@@ -1,115 +1,117 @@
 /*
     Copyright (c) 2007 - 2008 Volker Krause <vkrause@kde.org>
 
     This library is free software; you can redistribute it and/or modify it
     under the terms of the GNU Library General Public License as published by
     the Free Software Foundation; either version 2 of the License, or (at your
     option) any later version.
 
     This library is distributed in the hope that it will be useful, but WITHOUT
     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
     License for more details.
 
     You should have received a copy of the GNU Library General Public License
     along with this library; see the file COPYING.LIB.  If not, write to the
     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
     02110-1301, USA.
 */
 
 #include "attributefactory.h"
 
 #include "collectionrightsattribute_p.h"
 #include "entitydisplayattribute.h"
+#include "entityhiddenattribute.h"
 
 #include <KGlobal>
 
 #include <QtCore/QHash>
 
 using namespace Akonadi;
 
 /**
  * @internal
  */
 class DefaultAttribute : public Attribute
 {
   public:
     explicit DefaultAttribute( const QByteArray &type, const QByteArray &value = QByteArray() ) :
       mType( type ),
       mValue( value )
     {}
 
     QByteArray type() const { return mType; }
     Attribute* clone() const
     {
       return new DefaultAttribute( mType, mValue );
     }
 
     QByteArray serialized() const { return mValue; }
     void deserialize( const QByteArray &data ) { mValue = data; }
 
   private:
     QByteArray mType, mValue;
 };
 
 /**
  * @internal
  */
 class AttributeFactory::Private
 {
   public:
     QHash<QByteArray, Attribute*> attributes;
 };
 
 /**
  * @internal
  */
 class StaticAttributeFactory : public AttributeFactory
 {
   public:
     StaticAttributeFactory() : AttributeFactory(), initialized( false ) {}
     void init() {
       if ( initialized )
         return;
       initialized = true;
 
       // Register built-in attributes
       AttributeFactory::registerAttribute<CollectionRightsAttribute>();
       AttributeFactory::registerAttribute<EntityDisplayAttribute>();
+      AttributeFactory::registerAttribute<EntityHiddenAttribute>();
     }
     bool initialized;
 };
 
 K_GLOBAL_STATIC( StaticAttributeFactory, s_attributeInstance )
 
 
 AttributeFactory* AttributeFactory::self()
 {
   s_attributeInstance->init();
   return s_attributeInstance;
 }
 
 AttributeFactory::AttributeFactory()
   : d( new Private )
 {
 }
 
 AttributeFactory::~ AttributeFactory()
 {
   qDeleteAll( d->attributes );
   delete d;
 }
 
 void AttributeFactory::registerAttribute(Attribute *attr)
 {
   Q_ASSERT( !d->attributes.contains( attr->type() ) );
   d->attributes.insert( attr->type(), attr );
 }
 
 Attribute* AttributeFactory::createAttribute(const QByteArray &type)
 {
   Attribute* attr = self()->d->attributes.value( type );
   if ( attr )
     return attr->clone();
   return new DefaultAttribute( type );
 }
diff --git a/akonadi/entityhiddenattribute.cpp b/akonadi/entityhiddenattribute.cpp
new file mode 100644
index 000000000..ea7da259d
--- /dev/null
+++ b/akonadi/entityhiddenattribute.cpp
@@ -0,0 +1,61 @@
+/******************************************************************************
+ *
+ *  File : entityhiddenattribute.cpp
+ *  Creation date : Sat 1 Aug 2009 02:07:50
+ *
+ *  Copyright (c) 2009 Szymon Stefanek <s.stefanek at gmail dot com>
+ *
+ *  This library is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU Library General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
+ *  License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public License
+ *  along with this library; see the file COPYING.LIB.  If not, write to the
+ *  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ *  MA, 02110-1301, USA.
+ *
+ *****************************************************************************/
+
+#include "entityhiddenattribute.h"
+
+#include <QtCore/QByteArray>
+
+namespace Akonadi
+{
+
+EntityHiddenAttribute::EntityHiddenAttribute()
+{
+}
+
+EntityHiddenAttribute::~EntityHiddenAttribute()
+{
+}
+
+QByteArray Akonadi::EntityHiddenAttribute::type() const
+{
+  return "HIDDEN";
+}
+
+EntityHiddenAttribute * EntityHiddenAttribute::clone() const
+{
+  return new EntityHiddenAttribute();
+}
+
+QByteArray EntityHiddenAttribute::serialized() const
+{
+  return QByteArray();
+}
+
+void EntityHiddenAttribute::deserialize( const QByteArray &data )
+{
+  Q_ASSERT( data.isEmpty() );
+}
+
+} // namespace Akonadi
+
diff --git a/akonadi/entityhiddenattribute.h b/akonadi/entityhiddenattribute.h
new file mode 100644
index 000000000..eb941c8ed
--- /dev/null
+++ b/akonadi/entityhiddenattribute.h
@@ -0,0 +1,85 @@
+/******************************************************************************
+ *
+ *  File : entityhiddenattribute.h
+ *  Creation date : Sat 1 Aug 2009 02:07:50
+ *
+ *  Copyright (c) 2009 Szymon Stefanek <s.stefanek at gmail dot com>
+ *
+ *  This library is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU Library General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
+ *  License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public License
+ *  along with this library; see the file COPYING.LIB.  If not, write to the
+ *  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ *  MA, 02110-1301, USA.
+ *
+ *****************************************************************************/
+
+#ifndef _ENTITYHIDDENATTRIBUTE_H_
+#define _ENTITYHIDDENATTRIBUTE_H_
+
+#include <akonadi/attribute.h>
+
+
+namespace Akonadi {
+
+/**
+ * @short Attribute signaling that an entity should be hidden in the UI
+ *
+ * This class rappresents the attribute of all hidden items. The hidden
+ * items shouldn't be displayed in UI applications (unless in some kind
+ * of "debug" mode).
+ *
+ * @seealso Attribute
+ *
+ * @author Szymon Stefanek <s.stefanek@gmail.com>
+ * @since 4.4
+ */
+class AKONADI_EXPORT EntityHiddenAttribute : public Attribute
+{
+  public:
+
+    /**
+     * Creates a new entity hidden attribute.
+     */
+    EntityHiddenAttribute();
+
+    /**
+     * Destroys the entity hidden attribute.
+     */
+    ~EntityHiddenAttribute();
+
+  public:
+
+    /**
+     * Reimplemented from Attribute
+     */
+    QByteArray type() const;
+
+    /**
+     * Reimplemented from Attribute
+     */
+    EntityHiddenAttribute * clone() const;
+
+    /**
+     * Reimplemented from Attribute
+     */
+    QByteArray serialized() const;
+
+    /**
+     * Reimplemented from Attribute
+     */
+    void deserialize( const QByteArray &data );
+
+}; // EntityHiddenAttribute
+
+} // namespace Akonadi
+
+#endif //!_ENTITYHIDDENATTRIBUTE_H_