Seventh Review Conference in 2011 established an Article X database, which matches voluntary requests and offers for assistance and cooperation among States Parties and international organizations. Membership and joining the BWC The BWC has 185 States Parties as of February 2023, with South Sudan the most recent to become a party. Four states have signed but not ratified the treaty: Egypt, Haiti, Somalia, and Syria. Nine additional states have neither signed nor acceded to the treaty: Chad, Comoros, Djibouti, Eritrea, Israel, Kiribati, Micronesia, South Sudan and Tuvalu. For two of these 13 states not party to the convention, the process of joining is well advanced, while an additional four states have started the process. The BWC's degree of universality remains low compared to other weapons of mass destruction regimes, including the Chemical Weapons Convention with 193 parties and the Treaty on the Non-Proliferation of Nuclear Weapons with 191 parties. States can join the BWC through either ratification, accession or succession, in accordance with their national constitutional processes, which often require parliamentary approval. Ratification applies to states which had previously signed the treaty before it entered into force in 1975. Since then, signing the treaty is no longer possible, but states can accede to it. Succession concerns newly independent states that accept to be bound by a treaty that the predecessor state had joined. The Convention enters into force on the date when an instrument of ratification, accession, or succession is deposited with at least one of the depositary governments (the Russian Federation, the United Kingdom, and the United States). Several countries made reservations when ratifying the BWC declaring that it did not imply their complete satisfaction that the treaty allows the stockpiling of biological agents and toxins for "prophylactic, protective or other peaceful purposes", nor should it imply recognition of other countries they do not recognize. Verification and compliance Confidence-building measures At the Second Review Conference in 1986, BWC States Parties agreed to strengthen the treaty by exchanging annual confidence-building measures (CBMs). These politically binding reports aim to prevent or reduce the occurrence of ambiguities, doubts and suspicions, and at improving international cooperation on peaceful biological activities. CBMs are the main formal mechanism through which States Parties regularly exchange compliance-related information. After revisions by the Third, Sixth, and Seventh Review Conferences, the current CBM form requires states to provide information annually on six issues (CBM D was deleted by the