Some special definitions according to international laws:

Forced disappearance is the arrest, detention, abduction or any other form of deprivation of liberty committed by State officials or a group of individuals or persons, followed by denial to recognise a person’s deprivation of liberty or concealment of his or her fate or whereabouts, which deprives him or her from legal protection.

Missing person: Each person where relatives are unaware of his or her whereabouts and who is reported to have disappeared on the basis of reliable information related to an international or non-international armed conflict, internal violence or as a result of interference by another official or actual authority.

Arbitrary detention: The arrest or detention of individuals in cases, where there is no evidence or detention process that is not part of the legal process, such as without a warrant issued by a judicial body.

Torture: is one of the worst crimes. It is prohibited in times of peace and times of conflicts. All the justifications for torture are of no importance. The Convention on Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment has been adopted in an international convention.

You can reach the International Convention for the Protection of All Persons from Enforced Disappearance – OHCHR and the Convention Against Torture.

What is the International Day of Enforced Disappearance?

In the General Assembly Resolution 65/209 of 21 December 2010, the General Assembly expressed its particular concern at the increasing incidences of enforced or involuntary disappearances in various regions of the world, including arrest, detention and abduction.
The General Assembly in the same Resolution welcomed the adoption of the International Convention for the Protection of Persons from Enforced Disappearance and decided to declare August 30th as the International Day for the Victims of Enforced Disappearance to be observed from 2011.