Number decoration

Currency is useful.
But this doesn’t cover all cases.
And I don't understand durations, which currently display without any formatting (so what’s the difference from a simple number?).

We’ll need to add “year(s),” “day(s),” “s,” “min,” etc for duration.
And all the other cases: I need to include degrees “°,” for example, and distances (meters in my case, but it could be centimeters, etc.).

Maybe offer custom formatting?