In fact, the word annulment is not used in the law of the church. When this erroneous word is applied to a declaration of nullity, it signifies that the entire relationship between the spouses is wiped away or erased, including the legitimacy of children. This is one reason the word is wrong and not used in church law. It was a marriage contracted in violation of an impediment, condition or defective consent, but in good faith on the part of one or both of the contracting parties. Second, the misappropriation of the term illegitimate indicates a misunderstanding of legitimacy.
Legitimacy is a legal term, or construct, that is held by many legal systems throughout the world.
The term indicates knowledge of a child's paternity. The term legitimacy connotes that a child's father is the husband of the child's mother at the time of birth. In no way could a declaration of nullity deny a child's paternity. At the time of birth, the legally presumed relationship between the child's father and mother was indeed that of husband and wife. A declaration of nullity does not deny this.