A punishment platoon was an organisation, like the army, only to punish.
One punishment platoon was sent to the abandoned theme park, Hedgewick's World of Wonders, where they fought the revived Cybermen. The group's equipment included five hand pulses and one anti-cyber-gun[statement unclear]. After the Eleventh Doctor arrived on the planet, he made Clara Oswald the platoon's leader. (TV: Nightmare in Silver)