Boele-Woelki, Katharina Keywords: Family law | Private international law | Choice of law | Unification of law | Law of contracts | Model law | Legal principles | Conventions | Directives | International law and domestic law | Mots clefs: ABSTRACT Traditionally, conflict of law rules designate only national substantive law as the applicable law. Many unifying and harmonizing substantive law instruments of both States and non-State organizations, however, are designed specifically for application to cross-border relationships. Achieving …