We seem to be getting occasional questions that are more or less of a political/religious mix at times concerning Vatican City and the pope as the head of state. As a country the Vatican or Vatican City State is addressed officially as the Holy See by other governments.
My question was prompted by this one on the main site. When questions involve Vatican diplomacy or involve ambassadors of the Holy See, then a Holy See tag should be employed.
The Holy See in its' second section is defined as follows:
Second Section. Section for Relations with States or Second Section has the specific duty of attending to matters which involve civil governments. It has responsibility for (1) the Holy See's diplomatic relations with states, including the establishment of concordats or similar agreements; (2) for the Holy See's presence in international organizations and conferences; (3) in special circumstances, by order of the Supreme Pontiff and in consultation with the competent dicasteries of the Curia, provides for appointments to particular Churches, and for their establishment or modification; (4) in close collaboration with the Congregation for Bishops, it attends to the appointment of bishops in countries which have entered into treaties or agreements with the Holy See in accordance with the norms of international law. The Second Section is headed by an archbishop, the secretary for relations with states, who is aided by a prelate, the undersecretary for relations with states, and assisted by cardinals and bishops. - The Cardinals of the Holy Roman Church
Here are a few more: