Article — Wouters, Manual of Moral Theology
Article XIII. Legal Relationship
802.
I. The notion was explained in n. 760.
II. Existence of the impediment. Those who by civil law are held incapable of entering nuptials between themselves because of legal relationship arising from adoption cannot, by force of canon law, validly contract marriage between themselves (canon 1080). In order to know whether and between whom this impediment exists, recourse must be had to the civil laws of the country, and the matter must be decided according to their norm.
The diriment impediment is in force in Italy, Spain, Brazil, Bolivia, Colombia, Guatemala, and Peru.1
1 Wernz-Vidal, op. cit., n. 191; Aertnys-Damen, op. cit., II, n. 771.