Type I vs. Type O

Type I, the Australian/New Zealand standard, uses two flat pins angled in a V-shape plus a flat earth pin. China and Argentina use dimensionally similar but genuinely incompatible variants -- Chinese plugs don't physically fit, and Argentine plugs fit but with reversed polarity.

Type O is Thailand's standard, introduced in 2006 -- three round pins whose earth-pin offset happens to numerically match Type B's, letting Thailand's real-world hybrid sockets also accept American Type A/B and European Type C plugs. Pure single-standard Type O outlets barely exist in practice.