"Acknowledgement, by an accredited and impartial body, of the compliance of a product, service, organisation or staff, with requirements set out in a reference guide. The certification provides the proof, by way of a certificate, that a system has been implemented in accordance with a reference guide, and that it is functional" (CESE, La certification des entreprises dans le domaine de la santé au travail [The certification of companies in the field of workplace health], opinion, 2010).