Keywords:
Approved organizations, Certification, Certification (approval), Classification systems, Conformity, Definitions, Enterprises, Maintenance, Materials, Metallic, Metallic materials, Operation, Production, Proof of suitability, Qualifications, Quality assurance, Railway applications, Railway vehicle components, Railway vehicle construction, Railway vehicles, Railways, Repair, Specification (approval), Suitability, Welding, Welding engineering, Welding processes, Welding shops, Welding supervisors, Welding work