An asset version is protected from being purged regardless of the purge cut-off date if any of the following conditions is true:
It is the head version of that asset.
It is the predecessor version of an asset that is checked out to a project. Predecessor versions must be retained in order to detect and resolve potential version conflicts.
It is referenced by another asset that cannot be purged—for example, because the second asset is checked out to a project.
Purge has no effect on the working versions of assets that are checked out to a project.
After the purge completes, the PurgingService verifies that no protected versions were inadvertently deleted. Each purge executes under transaction control, so any verification failure causes the entire purge to roll back. In the unlikely event of purge rollback, you can contact ATG Customer Support for help diagnosing the problem before retrying the purge operation.