Abstract: Additional data is associated with existing directory service object instances by creating instances of object classes in an Application Partition. The additional data is added to one or more attribute(s) of the created instances; the created instances are associated with existing object instances by setting the value of a backlink attribute in the created instances to be the same as a partition link value in the existing object instances. The created instances may be members of object classes which were already existing in the schema of the directory service, the created instances may be members of an existing object class which has attributes which are modified for this purpose, or the created instances may be members of a new object class created for this purpose. The additional data, backlink, and partition link values may be stored as a normal value for the chosen attribute(s) or as pseudo-values.