When I first flew the Puma we always had Nav lights on, day and night. Now this was in the days when we did lots of night work, but didn't do much NVG (you know when the auth sheet was filled up with all the guff out of GASOs about exactly what you were going to do!)
Anyway, in everything I've flown since (fixed wing) I have always felt the desire to do the same, ie Nav lights on day and night. I'm frequently told that they should not be used during the day; is this correct? Having observed other fleets there appears to be a bit of a mix. Most of the Tonkas that I see during the day do have Nav lights on.