The essay focuses on the use of the written form in labor law (especially with reference to the genesis of the relationship), also to test the validity of formalism as a technique for protecting the worker's contractual weakness and limiting individual autonomy in the face of decline of the technique of inderogability. The A. demonstrates how over time the protective function of the formal constraint has weakened which, where prescribed, mostly serves to guarantee interests of a general nature and to satisfy the need for certainty of the rules; it is, therefore, a formalism that is entirely functional to information efficiency but certainly not to effectively guarantee the worker. Hence the importance of Riccardo Del Punta's invitation to use those regulatory techniques most functional to the defense of the values of labor law.