Class properties (Advanced tab)

Primary ID
The GUID that uniquely identifies this class.
Alias IDs
Identification used to enable users to perform queries across object stores. Content Engine uses alias IDs to identify classes that are semantically the same. To add or remove alias IDs click Assign or Unassign.
Allow Instances
Whether the class allows instances of itself to be created.
Allow Subclasses
Whether the class allows subclasses of itself to be created.
Allow Property Addition
Whether user-defined properties may be added to the class.
Hidden
Whether the class is marked as hidden.