This reports the address of whichever appliance became the standby as a result of a specific historical switchover event, the counterpart to carSWHistActiveNodeAddress, completing the record of both roles for that past event. An admin cross-referencing this against carSWHistActiveNodeAddress for the same history row confirms exactly which node ended up in which role after that particular switchover. For example, a history row showing this address matching what's currently reported by carMyAddress on one of the physical appliances confirms that specific appliance ended up as standby after that recorded event.