Hyuuga Clan policies section 7 exhibit 300
''Second born of the clan leader must be branded with a curse mark to secure the order within clan. In the case that first born's refusal to be heir he/she will be branded by the mark and the title shall be inherited by an available sibling.''
Source DB 4
''Second born of the clan leader must be branded with a curse mark to secure the order within clan. In the case that first born's refusal to be heir he/she will be branded by the mark and the title shall be inherited by an available sibling.''
Source DB 4
I got the translation copy from my cousin in Japan.