Patria Potestas ("Power of the Father") was a law recreated by Caesar Invanolo Buntari as part of his father's cultural reforms. It gives the male head of a family absolute control over all his legitimate and adopted children and other descendants in the male line.
As head of the family he is supposed to nurture and maintain his children, but may also have utter control over their lives. If they disobey him, he may punish them as he sees fit. If they dishonor him or the family name he may even kill them.
The side-effect of this law is that it removed equal rights and suffrage from female citizens. Women are restricted in what careers they may follow and cannot serve in political office. Their father must make all decisions for them until they are married, and even then must obey their husband.
Women who are Terran citizens can still join the military, but are restricted in what service arms they may serve in. They also cannot rise above the rank of Centurion Maximus.