diff --git a/lib/composer/autoload_classmap.php b/lib/composer/autoload_classmap.php
index d76a0e797..f1568a072 100644
--- a/lib/composer/autoload_classmap.php
+++ b/lib/composer/autoload_classmap.php
@@ -541,10 +541,12 @@ return array(
     'Combodo\\iTop\\Forms\\Validator\\AttributeExist' => $baseDir . '/sources/Forms/Validator/AttributeExist.php',
     'Combodo\\iTop\\Forms\\Validator\\AttributeExistValidator' => $baseDir . '/sources/Forms/Validator/AttributeExistValidator.php',
     'Combodo\\iTop\\PhpParser\\Evaluation\\PhpExpressionEvaluator' => $baseDir . '/sources/PhpParser/Evaluation/PhpExpressionEvaluator.php',
+    'Combodo\\iTop\\PropertyTree\\AbstractProperty' => $baseDir . '/sources/PropertyTree/AbstractProperty.php',
     'Combodo\\iTop\\PropertyTree\\CollectionOfTrees' => $baseDir . '/sources/PropertyTree/CollectionOfTrees.php',
     'Combodo\\iTop\\PropertyTree\\CollectionOfValues' => $baseDir . '/sources/PropertyTree/CollectionOfValues.php',
     'Combodo\\iTop\\PropertyTree\\Property' => $baseDir . '/sources/PropertyTree/Property.php',
     'Combodo\\iTop\\PropertyTree\\PropertyTree' => $baseDir . '/sources/PropertyTree/PropertyTree.php',
+    'Combodo\\iTop\\PropertyTree\\ValueType\\AbstractValueType' => $baseDir . '/sources/PropertyTree/ValueType/AbstractValueType.php',
     'Combodo\\iTop\\PropertyTree\\ValueType\\ValueTypeChoice' => $baseDir . '/sources/PropertyTree/ValueType/ValueTypeChoice.php',
     'Combodo\\iTop\\PropertyTree\\ValueType\\ValueTypeClassAttribute' => $baseDir . '/sources/PropertyTree/ValueType/ValueTypeClassAttribute.php',
     'Combodo\\iTop\\PropertyTree\\ValueType\\ValueTypeClassAttributeGroupBy' => $baseDir . '/sources/PropertyTree/ValueType/ValueTypeClassAttributeGroupBy.php',
diff --git a/lib/composer/autoload_static.php b/lib/composer/autoload_static.php
index 2c4e23ffe..c9679a601 100644
--- a/lib/composer/autoload_static.php
+++ b/lib/composer/autoload_static.php
@@ -927,10 +927,12 @@ class ComposerStaticInit7f81b4a2a468a061c306af5e447a9a9f
         'Combodo\\iTop\\Forms\\Validator\\AttributeExist' => __DIR__ . '/../..' . '/sources/Forms/Validator/AttributeExist.php',
         'Combodo\\iTop\\Forms\\Validator\\AttributeExistValidator' => __DIR__ . '/../..' . '/sources/Forms/Validator/AttributeExistValidator.php',
         'Combodo\\iTop\\PhpParser\\Evaluation\\PhpExpressionEvaluator' => __DIR__ . '/../..' . '/sources/PhpParser/Evaluation/PhpExpressionEvaluator.php',
+        'Combodo\\iTop\\PropertyTree\\AbstractProperty' => __DIR__ . '/../..' . '/sources/PropertyTree/AbstractProperty.php',
         'Combodo\\iTop\\PropertyTree\\CollectionOfTrees' => __DIR__ . '/../..' . '/sources/PropertyTree/CollectionOfTrees.php',
         'Combodo\\iTop\\PropertyTree\\CollectionOfValues' => __DIR__ . '/../..' . '/sources/PropertyTree/CollectionOfValues.php',
         'Combodo\\iTop\\PropertyTree\\Property' => __DIR__ . '/../..' . '/sources/PropertyTree/Property.php',
         'Combodo\\iTop\\PropertyTree\\PropertyTree' => __DIR__ . '/../..' . '/sources/PropertyTree/PropertyTree.php',
+        'Combodo\\iTop\\PropertyTree\\ValueType\\AbstractValueType' => __DIR__ . '/../..' . '/sources/PropertyTree/ValueType/AbstractValueType.php',
         'Combodo\\iTop\\PropertyTree\\ValueType\\ValueTypeChoice' => __DIR__ . '/../..' . '/sources/PropertyTree/ValueType/ValueTypeChoice.php',
         'Combodo\\iTop\\PropertyTree\\ValueType\\ValueTypeClassAttribute' => __DIR__ . '/../..' . '/sources/PropertyTree/ValueType/ValueTypeClassAttribute.php',
         'Combodo\\iTop\\PropertyTree\\ValueType\\ValueTypeClassAttributeGroupBy' => __DIR__ . '/../..' . '/sources/PropertyTree/ValueType/ValueTypeClassAttributeGroupBy.php',
diff --git a/sources/PropertyTree/AbstractProperty.php b/sources/PropertyTree/AbstractProperty.php
index f91b8f87f..377f414fd 100644
--- a/sources/PropertyTree/AbstractProperty.php
+++ b/sources/PropertyTree/AbstractProperty.php
@@ -11,6 +11,8 @@ use Combodo\iTop\PropertyTree\ValueType\AbstractValueType;
 
 abstract class AbstractProperty
 {
+	/** @var array<AbstractProperty> */
+	protected array $aChildren;
 	private ?AbstractValueType $oValueType;
 
 	public function GetValueType(): ?AbstractValueType
@@ -23,4 +25,13 @@ abstract class AbstractProperty
 		$this->oValueType = $oValueType;
 	}
 
+	public function AddChild(AbstractValueType $oValueType): void
+	{
+		$this->aChildren[] = $oValueType;
+	}
+
+	public function GetChildren(): array
+	{
+		return $this->aChildren;
+	}
 }
diff --git a/sources/alias.php b/sources/alias.php
index 7c5bdfd54..daec9b21e 100644
--- a/sources/alias.php
+++ b/sources/alias.php
@@ -9,6 +9,16 @@
 
 use Combodo\iTop\Application\UI\Base\Component\Input\Select\SelectUIBlockFactory;
 use Combodo\iTop\Application\UI\Base\Layout\ActivityPanel\CaseLogEntryForm\CaseLogEntryFormFactory;
+use Combodo\iTop\PropertyTree\CollectionOfTrees;
+use Combodo\iTop\PropertyTree\CollectionOfValues;
+use Combodo\iTop\PropertyTree\Property;
+use Combodo\iTop\PropertyTree\PropertyTree;
+use Combodo\iTop\PropertyTree\ValueType\ValueTypeChoice;
+use Combodo\iTop\PropertyTree\ValueType\ValueTypeClassAttribute;
+use Combodo\iTop\PropertyTree\ValueType\ValueTypeClassAttributeGroupBy;
+use Combodo\iTop\PropertyTree\ValueType\ValueTypeInteger;
+use Combodo\iTop\PropertyTree\ValueType\ValueTypeLabel;
+use Combodo\iTop\PropertyTree\ValueType\ValueTypeOQL;
 
 class_alias(\Combodo\iTop\Application\UI\Hook\iKeyboardShortcut::class, 'iKeyboardShortcut');
 class_alias(\Combodo\iTop\Application\UI\Base\Component\DataTable\DataTableConfig\DataTableConfig::class, 'DataTableConfig');
@@ -100,14 +110,14 @@ class_alias(\Combodo\iTop\Core\AttributeDefinition\AttributeURL::class, 'Attribu
 class_alias(\Combodo\iTop\Core\AttributeDefinition\iAttributeNoGroupBy::class, 'iAttributeNoGroupBy');
 class_alias(\Combodo\iTop\Core\AttributeDefinition\MissingColumnException::class, 'MissingColumnException');
 
-class_alias(Combodo\iTop\PropertyTree\PropertyTree::class, 'Combodo-PropertyTree');
-class_alias(Combodo\iTop\PropertyTree\Property::class, 'Combodo-Property');
-class_alias(Combodo\iTop\PropertyTree\CollectionOfValues::class, 'Combodo-CollectionOfValues');
-class_alias(Combodo\iTop\PropertyTree\CollectionOfTrees::class, 'Combodo-CollectionOfTrees');
+class_alias(PropertyTree::class, 'Combodo-PropertyTree');
+class_alias(Property::class, 'Combodo-Property');
+class_alias(CollectionOfValues::class, 'Combodo-CollectionOfValues');
+class_alias(CollectionOfTrees::class, 'Combodo-CollectionOfTrees');
 
-class_alias(Combodo\iTop\PropertyTree\ValueType\ValueTypeLabel::class, 'Combodo-ValueTypeLabel');
-class_alias(Combodo\iTop\PropertyTree\ValueType\ValueTypeOQL::class, 'Combodo-ValueTypeOQL');
-class_alias(Combodo\iTop\PropertyTree\ValueType\ValueTypeClassAttributeGroupBy::class, 'Combodo-ValueTypeClassAttributeGroupBy');
-class_alias(Combodo\iTop\PropertyTree\ValueType\ValueTypeChoice::class, 'Combodo-ValueTypeChoice');
-class_alias(Combodo\iTop\PropertyTree\ValueType\ValueTypeClassAttribute::class, 'Combodo-ValueTypeClassAttribute');
-class_alias(Combodo\iTop\PropertyTree\ValueType\ValueTypeInteger::class, 'Combodo-ValueTypeInteger');
+class_alias(ValueTypeLabel::class, 'Combodo-ValueTypeLabel');
+class_alias(ValueTypeOQL::class, 'Combodo-ValueTypeOQL');
+class_alias(ValueTypeClassAttributeGroupBy::class, 'Combodo-ValueTypeClassAttributeGroupBy');
+class_alias(ValueTypeChoice::class, 'Combodo-ValueTypeChoice');
+class_alias(ValueTypeClassAttribute::class, 'Combodo-ValueTypeClassAttribute');
+class_alias(ValueTypeInteger::class, 'Combodo-ValueTypeInteger');