They regulate the succession to the Crown of France: customary rules released gradually to solve serious practical situations, they ensure the continuity of the lineage and the state and thereby guarantee civil peace. Not to be written, they have not less force and were always observed.
– The succession to the Crown is hereditary from male to male by order of primogeniture;
– The Crown is unavailable in France: the reigning king can not change the order of succession, he can not abdicate or disinherit or deterred a Prince of the blood;
– Succession is instant: “The King is dead, long live the King”;
– The King of France must be Catholic, born of a Catholic marriage, canonically valid. However, subjects have no obligation to embrace the Catholic faith.