1. Ambassadors Extraordinary and Plenipotentiary and Apostolic Nuncio (the latter is always the Dean of the Diplomatic Corps in catholic countries);
2. Ministers Plenipotentiary;
3. Charges d’Affaires ad hoc or pro tempore
4. Charges d’Affaires ad interim (Embassies);
5. Charge d’Affaires ad interim (Legations).
Heads of Mission and Ministers Plenipotentiary are ranked among themselves according to the date and time of the presentation of their Letters (or the date of arrival and presentation of copies of the Letters).