For the purposes of this Chapter, a parent or grandparent of a person shall be deemed to be a citizen of Nigeria if at the time of the birth of that person such parent or grandparent would have possessed that status by birth if he had been alive on the date of independence; and in this section, “the date of independence” has the meaning assigned to it in section 25 (2) of this Constitution.
For citizenship by birth, the parents or grandparents of such a person must have been citizens by birth at the date of independence
SECTION 31 (1)
The president may make regulations, not inconsistent with this Chapter, prescribing all matters which are required or permitted to be prescribed or which are necessary or convenient to be prescribed for carrying out or giving effect to the provisions of this Chapter, and for granting special immigrant status with full residential rights to non-Nigerian spouses of citizens of Nigeria who do not wish to acquire Nigerian citizenship.
Basically, this section empowers the president to make rules that will enforce the provisions of this chapter dealing with citizenship. It also provides for a special status with residential rights for spouses of Nigerians who do not want to be citizens of Nigeria.
SECTION 31 (2)
Any regulations made by the president pursuant to the provisions of this section shall be laid before the National Assembly.
All rules made under this section shall be presented to the National Assembly for ratification and codification. (The president cannot actually make a Law, only the National Assembly can do so)