Though not referred in the Code as a domicile of origin, a child's place of origin is fixed by the place where his father had his domicile or, in defect of domicile, his quasi-domicile when the child was born, or where the mother had hers if the child was illegitimate or posthumous; if the parents were vagi it is the place where the child was born; if the child was a foundling the place where it was discovered.
Source: wiktionary