This paper discusses the problems that arise in the present-day Law of Obligations, in connection with the classification of contracts into nominate and in nominate contracts. The analysis contains a theoretical examination of the said contracts, their sub-types (linked, joined, mixed and atypical) their qualification and interpretation, the conflict of laws in the domain of contracts, particularly in view of public policy. Without referring to the classic institutions of obligation, i.e. contractual law, it is difficult or even impossible to understand the changing nature of contractual relations in our times, especially because they seem to be taking on completely new forms. What appear to be quite new forms of in nominate contracts, often on the very boundaries of public policy (public order),fair dealings, and prohibited contracts impose the need for a thorough and theoretical re-examination of the old classification of contracts into nominate and in nominate. In fact those modern, apparently, completely new contracts can be reduced to a kind of sub-type, which is between classic nominate and in nominate contracts. This premise could have significant, practical consequences because the legal life of such a contract will largely depend on the application of one or the other theory, e.g. the theory of absorption or the theory of combination with the possibility of relativising clear-cut types of contracts (e.g. the theory of absorption with certain specificities). It goes without saying that all of this, significantly eases the practical understanding and treatment of such contracts, especially from the viewpoint of the basic and, in a certain sense, most important question - their permissibility. Besides the theoretical approach, the paper also deals with all the legal aspects of one specific, in nominate contract, which provoked heated public debate and was the subject of several court cases. In conclusion, based on the doctrinal grounds, on experience in comparative law, as well as on foreign cases, the author gives his view of the resolution of these extremely complex problems which in our judicial practice would require the application both of general and of particular rules contained in the Law of Obligations, and the appropriate application of special legislation.