What conditions qualify as a valid hindrance or distraction call?

Rule 3.A.15 and Rule 11.J outline hindrances. If a ball from an adjacent court rolls into the active playing zone, either player may immediately call 'Ball on court!' to stop play, triggering an automatic replay of the rally. To be valid, the call must be made promptly as the interference occurs; a player cannot wait until after hitting an unforced error to claim a hindrance. Conversely, Rule 11.K forbids intentional distractions: shouting, stomping, waving paddles aggressively at the kitchen line to disrupt an opponent's overhead smash results in a technical warning or immediate point deduction.