China company registry entry-point matrix: six official doors, three rounds each

Per-round HTTP status codes for six official entry points to China's national company registry system — three national and three provincial — requested from a single Alibaba Cloud host inside mainland China on 15 August 2026, with two control hosts. The six doors returned six different answers: 521, 412, 400, 200, 302 and 404. One provincial entry point answers scripted clients normally, which matters because it means the refusal seen at the national entry points is a property of those specific doors rather than of the registry system as a whole. Method, limits and the landing page: https://currawongweb.com/verify/china-registry-entry-points/