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Complications with categorisation

While clear categories do exist, it is sometimes difficult to choose which category some individual heads of state belong to. In reality, the category to which each head of state belongs is assessed not by theory but by practice.

Constitutional change in Liechtenstein in 2003 gave its head of state, the Reigning Prince, constitutional powers that included a veto over legislation and power to dismiss the head of government and cabinet. It could be argued that the strengthening of the Prince's powers, vis-a-vis the Landtag (legislature), has moved Liechtenstein into the semi-presidential category. Similarly the original powers given to the Greek President under the 1974 Hellenic Republic constitution moved Greece closer to the French semi-presidential model.

Another complication exists with South Africa, in which the president is in fact elected by the National Assembly (legislature) and is thus similar, in principle, to a head of government in a parliamentary system but is also, in addition, recognised as the head of state. The offices of president of Nauru and president of Botswana are similar in this respect to the South African presidency.

Panama, during the military dictatorships of Omar Torrijos and Manuel Noriega, was nominally a presidential republic. However, the elected civilian presidents were effectively figureheads with real political power being exercised by the chief of the Panamanian Defense Forces.

Historically, at the time of the League of Nations (1920–1946) and the founding of the United Nations (1945), India's head of state was the monarch of the United Kingdom, ruling directly or indirectly as Emperor of India through the Viceroy and Governor-General of India.