Artikel 21

Where a diplomatic officer, consular agent or commissioner is authorized under Articles 15, 16 or 17 to take evidence -
(a) he may take all kinds of evidence which are not incompatible with the law of the State where the evidence is taken or contrary to any permission granted pursuant to the above Articles, and shall have power within such limits to administer an oath or take an affirmation;
(b) a request to a person to appear or to give evidence shall, unless the recipient is a national of the State where the action is pending, be drawn up in the language of the place where the evidence is taken or be accompanied by a translation into such language;
(c) the request shall inform the person that he may be legally represented and, in any State that has not filed a declaration under Article 18, shall also inform him that he is not compelled to appear or to give evidence;
(d) the evidence may be taken in the manner provided by the law applicable to the court in which the action is pending provided that such manner is not forbidden by the law of the State where the evidence is taken;
(e) a person requested to give evidence may invoke the privileges and duties to refuse to give the evidence contained in Article 11.