Hi Target,
As far as I know, and as illustrated in various WW2 pictures and books, Rangers did not adorn their helmets with specific (and colourful) 'Geneva Convention Markings' . There might have been exceptions, but I am not aware of any period illustrations proving they did !
This also applied to other troops involved in the D-Day landings, such as Infantry and Airborne, though the Navy and Special Engineers did paint similar insignia on their steel helmets ... later on, medical personnel started introducing Geneva Convention symbols on helmets, after having ascertained that the enemy generally respected the non-combatant status of military and civilian protected personnel .
I hope above helps .
Regards,
Alain
