The GENERIC field property creates a generic field property.
    You specify generic field properties only if you have made
    changes to the field type (CDD$DATA_ELEMENT) supplied by Oracle
    CDD/Repository, and the changes require generic field properties.

    You can specify the NOGENERIC keyword to remove a generic field
    property only if the changes you have made to CDD$DATA_ELEMENT
    indicate that this property is optional.