How is NEC used?

When there is no more specific option that applies.

The ancient Germanic tribes and the ancient Scandinavians used runes as an alphabet. Prior to that, they used runes for magic purposes, such as casting lots (divination) and spells of protection.

A model aeroplane is used for presentations and testing. Model planes are also used for fun. They are used model-plane clubs, aeroplane company headquarters and studios. (Bedroom, in my house)

That people wont work.

There still used for skating or you can give them to a friend for spare parts.