The IEC 62443 family of standards is an old acquaintance to most security managers for industrial systems. For more than ten years, it has been considered THE standard for industrial cybersecurity. It also serves as a "horizontal standard" offering a sector-agnostic baseline for industrial cybersecurity, upon which sector-specific requirements, e.g. for the energy sector, could be added by industry experts. In this blog we explore its implications for the energy sector.