Under the Hanoi government, "control" was a legal term used both as a verb and a noun. "Control" meant use of state power to deal with individuals who committed either civil or political crimes judged not serious enough to warrant imprisonment, but serious enough to deserve reform without detention. "Control" referred also to the status of an individual under such sentence (also one released from prison but considered not fully reformed). Hence it combined the condition of being on parole with that of being in the custody of the court or under state surveillance. A person under "control" had to report periodically to local authorities to account for his activities and detail his efforts to reform. He was proscribed from certain occupations, including teaching, publishing, practicing medicine or pharmacy, and operating a restaurant, hotel, or bookstore. Such restrictions were deemed legal because one under "control" was considered to have already forfeited some of his civil rights, at least temporarily.

The mechanism of "control," called the People's Organ of Control, was hierarchically organized and formally defined by the 1980 Constitution (Articles 127, 138, and 141). At the top was the Supreme People's Organ of Control, and at the bottom were the district and precinct organs of control. These institutions functioned to "control the observance of the law by the ministries, armed forces, state employees and citizens to exercise the right of public prosecution and to insure strict and uniform observance of the law." Their purview was "any act encroaching upon the interests of the State, the collective, or the lives, property, freedom, honor, and dignity of citizens." The underlying justification for their existence was that major internal security problems developed because of a breakdown in social discipline and that restoration of discipline was best achieved with a system of self-control or self-discipline. The system was composed of many activities: physical control re-education and reform indoctrination, emulation, and motivation and education. Its essence was organization and motivation, and in the hands of skilled cadres it could harness social pressure to induce new attitudes and ways of thinking.

Data as of December 1987