Each version of a policy has an associated version number. Edited policies automatically generate historical version numbers. Version numbering is implemented through the administration GUI using the edit sub-command of ssadm, which allows you to create new policy object files by name.
When a particular policy is superseded by a new version of that policy, the older version includes the policy object-specific information and the actual content of the common object registry instead of just a reference. Although you may find that the older policy version has become invalid due to changes that occurred in the network and hardware topology, it can be more consistent.