diff --git a/core/attributedef/AttributeMetaEnum.php b/core/attributedef/AttributeMetaEnum.php
new file mode 100644
index 000000000..7ddbbd88e
--- /dev/null
+++ b/core/attributedef/AttributeMetaEnum.php
@@ -0,0 +1,137 @@
+<?php
+
+/**
+ * A meta enum is an aggregation of enum from subclasses into an enum of a base class
+ * It has been designed is to cope with the fact that statuses must be defined in leaf classes, while it makes sense to
+ * have a superstatus available on the root classe(s)
+ *
+ * @package     iTopORM
+ */
+class AttributeMetaEnum extends AttributeEnum
+{
+    /**
+     * Useless constructor, but if not present PHP 7.4.0/7.4.1 is crashing :( (N°2329)
+     *
+     * @see https://www.php.net/manual/fr/language.oop5.decon.php states that child constructor can be ommited
+     * @see https://bugs.php.net/bug.php?id=79010 bug solved in PHP 7.4.9
+     *
+     * @param string $sCode
+     * @param array $aParams
+     *
+     * @throws \Exception
+     * @noinspection SenselessProxyMethodInspection
+     */
+    public function __construct($sCode, $aParams)
+    {
+        parent::__construct($sCode, $aParams);
+    }
+
+    public static function ListExpectedParams()
+    {
+        return array('allowed_values', 'sql', 'default_value', 'mapping');
+    }
+
+    public function IsNullAllowed()
+    {
+        return false; // Well... this actually depends on the mapping
+    }
+
+    public function IsWritable()
+    {
+        return false;
+    }
+
+    public function RequiresIndex()
+    {
+        return true;
+    }
+
+    public function GetPrerequisiteAttributes($sClass = null)
+    {
+        if (is_null($sClass)) {
+            $sClass = $this->GetHostClass();
+        }
+        $aMappingData = $this->GetMapRule($sClass);
+        if ($aMappingData == null) {
+            $aRet = array();
+        } else {
+            $aRet = array($aMappingData['attcode']);
+        }
+
+        return $aRet;
+    }
+
+    /**
+     * Overload the standard so as to leave the data unsorted
+     *
+     * @param array $aArgs
+     * @param string $sContains
+     *
+     * @return array|null
+     */
+    public function GetAllowedValues($aArgs = array(), $sContains = '')
+    {
+        $oValSetDef = $this->GetValuesDef();
+        if (!$oValSetDef) {
+            return null;
+        }
+        $aRawValues = $oValSetDef->GetValueList();
+
+        if (is_null($aRawValues)) {
+            return null;
+        }
+        $aLocalizedValues = array();
+        foreach ($aRawValues as $sKey => $sValue) {
+            $aLocalizedValues[$sKey] = $this->GetValueLabel($sKey);
+        }
+
+        return $aLocalizedValues;
+    }
+
+    /**
+     * Returns the meta value for the given object.
+     * See also MetaModel::RebuildMetaEnums() that must be maintained when MapValue changes
+     *
+     * @param $oObject
+     *
+     * @return mixed
+     * @throws Exception
+     */
+    public function MapValue($oObject)
+    {
+        $aMappingData = $this->GetMapRule(get_class($oObject));
+        if ($aMappingData == null) {
+            $sRet = $this->GetDefaultValue();
+        } else {
+            $sAttCode = $aMappingData['attcode'];
+            $value = $oObject->Get($sAttCode);
+            if (array_key_exists($value, $aMappingData['values'])) {
+                $sRet = $aMappingData['values'][$value];
+            } elseif ($this->GetDefaultValue() != '') {
+                $sRet = $this->GetDefaultValue();
+            } else {
+                throw new Exception('AttributeMetaEnum::MapValue(): mapping not found for value "' . $value . '" in ' . get_class($oObject) . ', on attribute ' . MetaModel::GetAttributeOrigin($this->GetHostClass(),
+                        $this->GetCode()) . '::' . $this->GetCode());
+            }
+        }
+
+        return $sRet;
+    }
+
+    public function GetMapRule($sClass)
+    {
+        $aMappings = $this->Get('mapping');
+        if (array_key_exists($sClass, $aMappings)) {
+            $aMappingData = $aMappings[$sClass];
+        } else {
+            $sParent = MetaModel::GetParentClass($sClass);
+            if (is_null($sParent)) {
+                $aMappingData = null;
+            } else {
+                $aMappingData = $this->GetMapRule($sParent);
+            }
+        }
+
+        return $aMappingData;
+    }
+}
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