> Are there any differences from the linguistic origin that could be used in the language code?

Unfortunately, no. Both names are standard Norwegian, meaning "the flat skerry" and "the black skerry", respectively. Looking at orthophoto, the skerry looks to be both relatively flat and black, so it's hard to argue that one name is more correct than the other.

For reference:
https://en.wikipedia.org/wiki/Skerry

> If you decide to use both notations, names will be suppressed more often because the next name is already waiting to be displayed.

I'm not intimately familiar with rendering practices for names, so I'm struggling a bit to understand exactly what you mean with suppression here. Could you expand a bit on this?

I see mentioned that Mapbox supports multiple names, but am not sure about carto behaviour. See: https://wiki.openstreetmap.org/wiki/Semi-colon_value_separator#Renderers

As an aside, the section on "Multiple names" in the article for the name key seems somewhat relevant: https://wiki.openstreetmap.org/wiki/Key:name