Comprehensive Nuclear-Test-Ban Treaty
The contracting states to the Comprehensive Nuclear-Test-Ban Treaty (CTBT) are the states that have signed and ratified the international agreement banning all nuclear explosions in all environments. Technically they will not be "parties" until the treaty enters into force, at which point these states will also be Member States of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), which comes into existence upon entry into force of the treaty. Non-contracting states are also listed, including those that are signatories and those are not. States Signatories are Members of the CTBTO Preparatory Commission.