In some states, the legal acceptability of common law marriage is very limited. Some couples, whether because there are no local formalities relevant to them or because they have strongly held prejudices against compliance with the local forms, decide to create a marriage either by a simple public exchange of vows (per verbis inter praesentes), or by habit and repute. Because the need for conformity between states requires respect for the legal systems, it is now very difficult to identify states with no local system for the celebration and registration of marriages, and even more difficult for the courts of one state to justify a decision to support the prejudices of two of its citizens against the laws of the second state. However, other states permit informal marriages to acquire legal status and, where this happens, there is no reason in principle why international recognition should not follow.
