property PropertiesList.AllowDuplicateEntries as Boolean
Specifies whether the Add method allows adding new properties with the same caption on the Name column.

TypeDescription
Boolean A Boolean expression that specifies whether the Add method allows adding new properties with the same name.
By default, the AllowDuplicateEntries property is True. If the AllowDuplicateEntries property is False, the Add method does not add a new property with a name that's already shown on the Name column.