Nationals of a State which belonged to the French Union and which has not entered into an undertaking with France as referred to in article L. 4111-3 who, on 14 July 1972, can prove that they were duly registered with the Order of Physicians, Dental Surgeons or Midwives, are authorised to continue practising their profession, provided that they have not been struck off the Register following a disciplinary sanction.