Artikel 16

A diplomatic officer or consular agent of a Contracting State may, in the territory of another Contracting State and within the area where he exercises his functions, also take the evidence, without compulsion, of nationals of the State in which he exercises his functions or of a third State, in aid of proceedings commenced in the courts of a State which he represents, if -
(a) a competent authority designated by the State in which he exercises his functions has given its permission either generally or in the particular case, and
(b) he complies with the conditions which the competent authority has specified in the permission.
A Contracting State may declare that evidence may be taken under this Article without its prior permission.