Star Trek: 10 Starfleet Rules You Never Knew Existed
2. The Starfleet Draft
It may come as a surprise to some that Starfleet actually practised conscription on rare occasions.
In Star Trek: The Motion Picture, McCoy, who had returned to civilian life after the Enterprise's five-year mission, was forced back into service by the 'reserve activation clause' in his Starfleet contract, which gave high-ranking officers the power to reinstate officers who had been previously discharged. As McCoy explained, 'In simpler language, Captain, they drafted me!' The reserve activation clause was simply a more gentle term for the same concept.
The Starfleet draft was further explained in the Discovery episode Choose Your Pain. Captain Lorca commissioned the work of the former criminal mutineer, Michael Burnham near the beginning of the series. To justify his actions to Admiral Cornwell, he cited regulation 13982, which apparently gave captains the power to draft literally anyone into service during times of war.