post, or, if he is unable to do so, by any competent authority of the sending State, to the Ministry for Foreign Affairs of the receiving State or to the authority designated by that Ministry. As a general rule, this notification shall be given in advance. The receiving State may make the admission as acting head of post of a person who is neither a diplomatic agent nor a consular officer of the sending State in the receiving State conditional on its consent. 3. The competent authorities of the receiving State shall afford assistance and protection to the acting head of post. While he is in charge of the post, the provisions of the present Convention shall apply to him on the same basis as to the head of the consular post concerned. The receiving State shall not, however, be obliged to grant to an acting head of post any facility, privilege or immunity which the head of the consular post enjoys only subject to conditions not fulfilled by the acting head of post. 4. When, in the circumstances referred to in paragraph 1 of this article, a member of the diplomatic staff of the diplomatic mission of the sending State in the receiving State is designated by the sending State as an acting head of post, he shall, if the receiving State does not object thereto, continue to enjoy diplomatic privileges and immunities. Article 16 Precedence as between heads of consular posts 1. Heads of consular posts shall rank in each class according to the date of the grant of the exequatur. 2. If, however, the head of a consular post before obtaining the exequatur is admitted to the exercise of his functions provisionally, his precedence shall be determined according to the date of the provisional admission; this precedence shall be maintained after the granting of the exequatur. 3. The order of precedence as between two or more heads of consular posts who obtained the exequatur or provisional admission on the same date shall be determined according to the dates on which their commissions or similar instruments or the notifications referred to in paragraph 3 of article 11 were presented to the receiving State. 4. Acting heads of posts shall rank after all heads of consular posts and, as between themselves, they shall rank according to the dates on which they assumed their functions as acting heads of posts as indicated in the notifications given under paragraph 2 of article 15. 5. Honorary consular officers who are heads of consular posts shall rank in each class after career heads of consular posts, in the order and according to the rules laid down in the foregoing paragraphs. 6. Heads of consular posts shall have precedence over consular officers not having that status. Article 17 Performance of diplomatic acts by consular officers 1. In a State where the sending State has no diplomatic mission and is not represented by a diplomatic mission of a third State, a consular officer may, with the consent of the receiving State, and 8