A multi-valued property that specifies the attributes that may be present on instances of this class. These are optional attributes that are not mandatory and, therefore, may or may not be present on an instance of this class. After creation of the class, this property cannot be changed. Each value is the lDAPDisplayName of an attribute. You must ensure that the attributes exist or will exist when the new class is written to the directory. If one of the attributes does not exist, the classSchema object will fail to be added to the directory. The full set of optional attributes for this class is the union of the systemMayContain and mayContain on this class as well as the systemMayContain and mayContain properties of all inherited classes.