residence until the adoption decree is entered, that he/she has been certified by his/her diplomatic or consular office or any appropriate government agency that he/she has the legal capacity to adopt in his/her country, and that his/her government allows the adoptee to enter his/her country as his/her adopted son/daughter: Provided, Further, That the requirements on residency and certification of the alien's qualification to adopt in his/her country may be waived for the following: (i) a former Filipino citizen who seeks to adopt a relative within the fourth (4th) degree of consanguinity or affinity; or (ii) one who seeks to adopt the legitimate son/daughter of his/her Filipino spouse; or (iii) one who is married to a Filipino citizen and seeks to adopt jointly with his/her spouse a relative within the fourth (4th) degree of consanguinity or affinity of the Filipino spouse; or (c) The guardian with respect to the ward after the termination of the guardianship and clearance of his/her financial accountabilities. Husband and wife shall jointly adopt, except in the following cases: (i) if one spouse seeks to adopt the legitimate son/daughter of the other; or (ii) if one spouse seeks to adopt his/her own illegitimate son/daughter: Provided, However, that the other spouse has signified his/her consent thereto; or (iii) if the spouses are legally separated from each other. In case husband and wife jointly adopt, or one spouse adopts the illegitimate son/daughter of the other, joint parental authority shall be exercised by the spouses. Section 8. Who May Be Adopted. – The following may be adopted: (a) Any person below eighteen (18) years of age who has been administratively or judicially declared available for adoption; (b) The legitimate son/daughter of one spouse by the other spouse; (c) An illegitimate son/daughter by a qualified adopter to improve his/her status to that of legitimacy; (d) A person of legal age if, prior to the adoption, said person has been consistently considered and treated by the adopter(s) as his/her own child since minority; (e) A child whose adoption has been previously rescinded; or