P.R. Laws tit. 31, § 504
Natural children are those born out of wedlock, from parents who, at the moment when such children were conceived or were born, could have intermarried with or without dispensation.
The natural child may be recognized by the father and mother conjointly or by one of them only either in the record of birth or in the testament or in any other public instrument.
The father is obliged to recognize the natural child:
(1) When there exists an indubitable statement in writing of this father wherein he expressly acknowledges his paternity.
(2) When the child has uninterruptedly enjoyed the condition as of a natural child of the defendant father justified by acts of the same father or of his family.
(3) When the mother was known to have lived in concubinage with the father, both during her pregnancy and at the time of the birth of the child.
(4) When the child may present any authentic evidence of paternity.
The mother shall likewise be obliged to recognize a natural child in the same cases as the father, and further where the act of the confinement and the identity of the child are fully established.
The child, if of age, cannot be recognized without his consent.
When the recognition of the minor is not made at the time of recording the birth or in the testament, the approval of the judge of the part of the Court of First Instance where the child resides, with the concurrence of the fiscal, shall be necessary.
History —Civil Code, 1930, § 125.