1. Where the objective rules and criteria for the exclusion and selection of economic operators requesting qualification in a qualification system include requirements relating to the economic and financial capacity of the economic operator, or to its technical and professional abilities, the economic operator may where necessary rely on the capacity of other entities, whatever the legal nature of the link between itself and those entities. With regard to criteria relating to the educational and professional qualifications of the service provider or contractor or those of the undertaking's managerial staff or to the relevant professional experience, economic operators may however only rely on the capacities of other entities where the latter will perform the works or services for which these capacities are required. Where an economic operator wants to rely on the capacities of other entities, it shall prove to the contracting entity that those resources will be available to it throughout the period of the validity of the qualification system, for example by producing a commitment by those entities to that effect.