Abstract: In this study we tried to render a practical content for the theoretical subject of contract classification. We managed to analyze the particular juridical effects of a certain type of contracts, depending on the specific clauses that they have embraced by the will of the parties or even the legislator. Thus, our scientific approach was oriented to the understanding of complex contractual constructions that unify under unique form elements considered to be antagonistic. The essence in finding legal recognition for complex contracts lays in the development of a clear regulatory mechanism applicable to them, from different contractual institutions, for which a uniform regulatory mechanism is already in place.

Key-words: contract classification, type of contracts, complex contract, elements of various contracts, coexisting systematic criteria, constitutive contractual parts, the unique type of provision, integrated or mixed contracts.