Should you signal the fact of parking a broken-down car on an area excluded from driving?

Why?

The car is standing on white diagonal hatching, marking P-21, which identifies an area closed to traffic. Since stopping there is prohibited, a stop caused by a breakdown must be properly signalled.

art. 50 ust. 1 pkt 2 lit. b Prawa o ruchu drogowym; znak P-21, § 90 ust. 5 rozporządzenia w sprawie znaków i sygnałów drogowych