“N” symbol on 12w UK iPad charger?

I’ve just bought a 12w iPad charger from the Apple department of John Lewis in London and it came boxed and sealed.

All of the symbols on the charger match the genuine symbols shown on the Apple website but there is an “N” symbol at the far left on this one which I can’t find any information anywhere?

Does anyone know what that “N” symbol stands for?

Thanks in advance.