Legal Dictionary of Pakistan

heres suus et necessarius

[Latin "one's own and necessary heir"] A free person subject to the decedent's potestas. ( These heirs were called necessary because they became heirs by law, not by the decedent's choice. But since this was also true of slaves, when named heirs in a will, the former class was designated suus et necessarius by way of distinction, the word suus denoting that the necessity arose from the relationship to the decedent.