In places where i fly, a moonless night means no horizon to reference off - those odd lights on the ground can blend into the ones in the sky too - and only a fool would fly 'visually' in these conditions.
Flown with primary reference to instruments, i believe it is reasonable to log as actual I.F.
Logging I.F time any time you fly under the IFR is bogus, or at cruise with the AP on.
At the end of he day, one has to be honest with ones self - and be able to back up your figures with demonstrated ability in the sim or on a check ride.