11. The Convention entered into force 1 January 2002 and as of July 2016 has 4 contracting States . 12. CPT delegations visit Contracting States periodically but may organise additional " ad hoc " visits if necessary. 13. They ensure the automatic mutual recognition of official decisions taken by one Contracting State in other Contracting States. 14. Each Contracting State may notify the ICAO Council of differences between SARPs and its own regulations and practices. 15. The foregoing facts do not reflect a Europe-wide failure by the Contracting States to properly implement the Directive. 16. However, a national court in one Contracting State may not revoke a European patent in another Contracting State . 17. However, a national court in one Contracting State may not revoke a European patent in another Contracting State. 18. They ensure the automatic mutual recognition of official decisions taken by one Contracting State in other Contracting States . 19. Those questions are to be answered by the domestic law selected by the courts of the contracting states . 20. The " election " of a contracting state correspondingly means electing it when demanding ( requesting ) the examination.
