 The system of citizenship registration was established by the "Irish Nationality and Citizenship Act, 1956".A person born outside Ireland to an Irish-citizen parent who was also born outside Ireland may acquire Irish citizenship by registering onto the Foreign Births Register or a Foreign Births Entry Book.Such people become Irish citizens from the date of registration, or for those registered on or before 30 June 1986, from their date of birth, or 17 July 1956 if they were born before that date.