Here in Australia, publications always use AUD. In Britain its the pound. BTC or gold would be my choice. Maybe XMR if the context is DNMs.
While it's true that you can have local units of account they all come back to the USD. sorry Australia. We can certainly argue that exceptions are made for countries that do not participate in the United States dollar homogeny. You mentioned BRICS. I think there are some nuances there, but basically you're right.