Surroundings v System Entropies

[katielam2G]

I attended a UA session and vaguely remember that for a reversible system, the universe entropy is equal to -Ssys while for a reversible system has a universe entropy of 0 so Ssurr=-Ssys

Is this statement correct? If so, why is it so?

[Travis Crane 1H]

When a process is reversible, delta Sunivese=0. Given the equation delta Suniverse=delta Ssys + delta Ssurr, when the process is reversible and Suniverse=0, the relation Ssurr=-Ssys is correct.