(1) If the parents have no family name and if only one of them has parental custody, the child receives the name that this parent has at the date of the birth of the child.
(2) The parent who has the sole parental custody for a child may, by declaration to the registry of births, deaths and marriages, give the child the name of the other parent. The giving of the name is subject to consent by the other parent and, if the child has reached the age of five, also consent by the child. The declarations must be publicly certified. The child’s consent is governed accordingly by section 1617c (1).