ISO 9241-210

An international standard specifying the principles and activities of human-centred design (HCD) for interactive systems. It defines a six-step iterative process — understanding context of use, specifying user requirements, producing design solutions, and evaluating against requirements — and explicitly includes users with disabilities in its scope. Widely used as the process backbone for accessibility work, participatory design, and usability engineering, and frequently cited alongside WCAG as evidence of design due diligence in accessibility conformance documentation.