diff --git a/core/attributedef/AttributeClass.php b/core/attributedef/AttributeClass.php
new file mode 100644
index 0000000000..dd48068fde
--- /dev/null
+++ b/core/attributedef/AttributeClass.php
@@ -0,0 +1,84 @@
+<?php
+
+/**
+ * An attribute that matches an object class
+ *
+ * @package     iTopORM
+ */
+class AttributeClass extends AttributeString
+{
+    const SEARCH_WIDGET_TYPE = self::SEARCH_WIDGET_TYPE_ENUM;
+
+    public static function ListExpectedParams()
+    {
+        return array_merge(parent::ListExpectedParams(), array('class_category', 'more_values'));
+    }
+
+    public function __construct($sCode, $aParams)
+    {
+        $this->m_sCode = $sCode;
+        $aParams["allowed_values"] = new ValueSetEnumClasses($aParams['class_category'], $aParams['more_values']);
+        parent::__construct($sCode, $aParams);
+    }
+
+    public function GetDefaultValue(DBObject $oHostObject = null)
+    {
+        $sDefault = parent::GetDefaultValue($oHostObject);
+        if (!$this->IsNullAllowed() && $this->IsNull($sDefault)) {
+            // For this kind of attribute specifying null as default value
+            // is authorized even if null is not allowed
+
+            // Pick the first one...
+            $aClasses = $this->GetAllowedValues();
+            $sDefault = key($aClasses);
+        }
+
+        return $sDefault;
+    }
+
+    /**
+     * @param array $aArgs
+     * @param string $sContains
+     *
+     * @return array|null
+     * @throws \CoreException
+     */
+    public function GetAllowedValues($aArgs = array(), $sContains = '')
+    {
+        $oValSetDef = $this->GetValuesDef();
+        if (!$oValSetDef) {
+            return null;
+        }
+
+        $aListClass = $oValSetDef->GetValues($aArgs, $sContains);
+        /* @since 3.3.0 remove elements in class_exclusion_list */
+        $sClassExclusionList = $this->GetOptional('class_exclusion_list', null);
+        if (!empty($sClassExclusionList)) {
+            foreach (explode(',', $sClassExclusionList) as $sClassName) {
+                unset($aListClass[trim($sClassName)]);
+            }
+        }
+
+        return $aListClass;
+    }
+
+    public function GetAsHTML($sValue, $oHostObject = null, $bLocalize = true)
+    {
+        if (empty($sValue)) {
+            return '';
+        }
+
+        return MetaModel::GetName($sValue);
+    }
+
+    public function RequiresIndex()
+    {
+        return true;
+    }
+
+    public function GetBasicFilterLooseOperator()
+    {
+        return '=';
+    }
+
+}
\ No newline at end of file