Probably it is the shield or crest with the heraldic lion (rampant = Old French for 'rearing up') with a viking battle ax and the Norwegian crown over it that identifies it as Norwegian rather than the O.S.
English = Official Service
Norwegian = Offisiell Service
(from Google Language)
From Wikipedia (Attitude of Animals in Heraldry):
http://en.wikipedia.org/wiki/Rampant#RampantLion Rampant

Further investigation reveiled:
The Coat of Arms of Norway is a crowned, golden lion rampant holding an axe with an argent (silver) blade, on a crowned, triangular and red escutcheon (main feature or background shield). Its elements originate from personal insignias for the royal house in the High Middle Ages, thus being among the oldest in Europe.
