Natural-born-citizen clause
A natural-born-citizen clause is a provision in some constitutions that certain officers, usually the head of state, must be "natural-born" citizens of that state, but there is no universally accepted meaning for the term natural-born. The constitutions of a number of countries contain such a clause but may define or interpret the term natural-born citizen differently.
Source: Wikipedia — Natural-born-citizen clause (CC BY-SA 4.0)