In 1955, the First UN Congress on the Prevention of Crime and the Treatment of Offenders adopted the Standard Minimum Rules for the Treatment of Prisoners. Known as the SMRs, these non-binding rules provide principles of good practice in the treatment of prisoners and the management of penal institutions such as jails, detention centres and correctional facilities. The SMRs were among the first international instruments aimed at protecting the rights of those accused of committing criminal offences.
The SMRs do not constitute a legally binding instrument that States sign and ratify. As such, States are not legally bound to comply. Still, national and international courts and human rights organizations refer to the SMRs to provide guidance in interpreting norms and standards with regards to prison populations. And the Convention Against Torture, which is legally binding, includes provisions some of which affect treatment of prisoners.