What use cases are covered by the ReportCaster RECOVERY=ON option?
If RECOVERY is enabled and the Reporting Server is stopped, the job will not run again because the Distribution Server will receive a disconnect from the Reporting Server and will tag the schedule as complete, though with errors. But since this was a clean shutdown, the TCP session will issue a disconnect notice to the Distribution Server which will tag the job as completed with errors. It will not run again.
However, if a schedule completes execution on the Reporting Server, but the Distribution Server is brought down before it completes the execution, the Distribution Server will not know anything about the final status of that schedule and never receive the output for distribution. It will not tag the schedule as complete. Once the Distribution Server is restarted, the schedule will run again because the RECOVERY=ON option was set. If you have the RECOVERY=OFF option set, the schedule will not be run again.
This last case is a simulation of what might happen if you had a network outage and communication between the Reporting Server and the Distribution Server is disabled for a while.