For the purposes of this Directive:
(a) "institution for occupational retirement provision", or "institution", means an institution, irrespective of its legal form, operating on a funded basis, established separately from any sponsoring undertaking or trade for the purpose of providing retirement benefits in the context of an occupational activity on the basis of an agreement or a contract agreed: - individually or collectively between the employer(s) and the employee(s) or their respective representatives, or - with self-employed persons, in compliance with the legislation of the home and host Member States, and which carries out activities directly arising therefrom;
(b) "pension scheme" means a contract, an agreement, a trust deed or rules stipulating which retirement benefits are granted and under which conditions;
(c) "sponsoring undertaking" means any undertaking or other body, regardless of whether it includes or consists of one or more legal or natura