(b) help to enhance the power, prestige and good name of Nigeria, defend Nigeria and render such national service as may be required; (c) respect the dignity of other citizens and the rights and legitimate interests of others and live in unity and harmony and in the spirit of common brotherhood; (d) make positive and useful contribution to the advancement, progress and wellbeing of the community where he resides; (e) render assistance to appropriate and lawful agencies in the maintenance of law and order; and (f) declare his income honestly to appropriate and lawful agencies and pay his tax promptly. Chapter III Citizenship 25. (1) The following persons are citizens of Nigeria by birth-namely(a) every person born in Nigeria before the date of independence, either of whose parents or any of whose grandparents belongs or belonged to a community indigenous to Nigeria; Provided that a person shall not become a citizen of Nigeria by virtue of this section if neither of his parents nor any of his grandparents was born in Nigeria. (b) every person born in Nigeria after the date of independence either of whose parents or any of whose grandparents is a citizen of Nigeria; and (c) every person born outside Nigeria either of whose parents is a citizen of Nigeria. (2) In this section, "the date of independence" means the 1st day of October 1960. 26. (1) Subject to the provisions of section 28 of this Constitution, a person to whom the provisions of this section apply may be registered as a citizen of Nigeria, if the President is satisfied that (a) he is a person of good character; (b) he has shown a clear intention of his desire to be domiciled in Nigeria; and (c) he has taken the Oath of Allegiance prescribed in the Seventh Schedule to this Constitution. (2) the provisions of this section shall apply to(a) any woman who is or has been married to a citizen of Nigeria; or (b) every person of full age and capacity born outside Nigeria any of whose grandparents is a citizen of Nigeria.