(1) Monarch. Chief of state is a monarch (either hereditary or elective) or a regent functioning on a monarch's behalf.

(2) President. Chief of state is a president who may function as chief executive or merely as titular head of state, in which case he will possess little effective power. The presiding officer of a legislative assembly or state council may qualify for the coding, even though the formal title may be that of "chairman".

(3) Military. A situation in which a member of the nation's armed forces is recognized as the formal head of government. In case of conflict between (2) and (3), coding is determined on the basis of whether the incumbent's role is intrinsically military or civilian in character.

(4) Other. In practice, this category is used when no distinct head of state can be identified. It includes any distinct head of state not included in (1)-(3), such as a theocratic ruler, as well as non-military bodies serving in a collegial capacity.