...
- After a Petition is submitted, if the Petitioner is not already a member of the CO (eg: self signup), then the Petitioner will be sent to the URL specified via Submission Redirect URL (if any).
- After the Enrollee confirms their email address (by clicking the link sent to them), they will be sent to the URL specified via Confirmation Redirect URL (if any).
- This setting should not be used for Account Linking enrollment.
- After the enrollment process has completed, the actor will be sent to the URL specified via Finalization Redirect URL (if any).
- If email confirmation is required and approval is not required, this setting will have no effect. Use Confirmation Redirect URL instead.
- If approval is required, the Approver will be redirected to the specified URL, not the Enrollee.
- This setting is available from Registry v3.1.0.
When a redirect is issued to one of these URLs, the session variable CoPetition.id will also be set. This allows a potential target URL within COmanage Registry to determine which Petition is currently in process. This is particularly useful for custom Plugins that wish to add functionality to the Enrollment Flow. 
This functionality is no longer present from v0.9.4. Use Enroller Plugins instead.
...