Can someone explain please

1) What _exactly_ is a domain mark?

2) Why does it accelerate failover and notably failback?

3) Do you need to regenerate / run a DomainMark job each time?

4) When SyncIQ is used to transfer a SmartLock directory, what is the expected domain mark that will be set? A synciq domain mark, a worm domain mark, or both? This last question might be a lot about inner workings, but essentially closes the circle and brings me back to question number 1: what is a domain mark?

Thanks