As for register in the case where the order of succession to the Imperial Throne was changed due to Crown Prince's fatal disease or serious accident, there is no major difference between the old and new Kotofu Rei (the old Article 28, the existing Article 4).
皇嗣に、不治の重患または重大な事故があるために、皇位継承の順序を変えたときの登録に関しては、新旧令に大きな違いはない（旧28条、現4条）。