The solutions of private international law in the absence of specific rules regulating international situations are limited. Moreover, there is a strong diversity of regulation of these situations in comparative law, and when the laws of the forum do not contemplate these situations, the foreign laws that contemplate them usually contain "criteria of application in space", so that they are applicable when there is a more or less close link between the members of the couple and the State in which they reside. This session will examine the possible solutions, ranging from the analogical application of matrimonial private international law to the thesis of "family rights and duties".