My mistake. JAR-FCL 1.080(c) (2)
Co-Pilot flight time
The holder of a pilot licence occupying a pilot seat as co-pilot may log all flight time as co-pilot flight time on an aeroplane on which more than one pilot is required under the type certification of the aeroplane, or the regulations under which the flight is conducted.
... and goes on to say that you can't log PICUS unless you are a co-pilot.
The differences you don't know about, when you change country ...