Originally Posted by
WineCountryUA
That means a single SWU can be used for the two (or more) segments as long there is no stopover over 12 hours.
Or, more importantly, any stopover longer than 12 hours requires a second instrument. The agents kept insisting I could cover SFO-IAD-<22 hour layover>-FCO with a single SWU and not have to use the CR-1 for the domestic portion.