Version: 1.0 Status: Normative Scope: Interactive software interfaces across all form factors (desktop, mobile, tablet, wearable, automotive, spatial), applicable by extension to any designed artifact (physical products, environments, signage systems).
Normative language: The key words MUST, MUST NOT, SHALL, SHOULD, SHOULD NOT, MAY are to be interpreted per RFC 2119. Requirements are individually numbered (P-x.y for strategic principles, C-x.y for cognitive/perceptual principles, T-x.y for trade-off resolution rules, V-x.y for verification procedures) to permit traceability in design reviews.