A reformant was a person on planet Betrisius III who had been convicted of a crime, and implanted with a neural mediator, which altered their mental processes and controlled their behavior during their mandated period of rehabilitation.
In the decades leading up to the mid 24th century, the authorities on Betrisius, specifically the Ministry of Reformation of the Lisqual province government, began to erode the rights of their reformants, forcing them into military service (as soldiers known as Morhenza), and arbitrarily extending their sentences in order to keep them as laborers.
In 2377, a year after formal first contact with the Federation, Dolanara, a former member of the Reformation Ministry, sought to expose these abuses by overriding the reformants' neural mediators and causing them to engage in acts of civil disobedience and violence. She was eventually stopped by the crew of the USS da Vinci, but the revelations of the reformants' treatment ensured Betrisius would not be allowed to join the Federation in the near future. (CoE eBook: Turn the Page)