This International Standard defines five levels of competence (defined in section 4) for persons acting in the field of cathodic protection, including survey, design, installation, testing and maintenance. It specifies a framework for establishing these competence levels and their minimum requirements. Competence levels apply to each of the following application sectors: on-land metallic structures; marine metallic structures; reinforced concrete structures; inner surfaces of metallic container structures. These application sectors are detailed in section 5. This International Standard defines the requirements to be used for establishing a certification scheme as defined in ISO/IEC 17024. This certification scheme is detailed in normative Annexes A, B and C.