Type K vs. Type O

Type K is Denmark's standard -- two round power pins plus a separate round earth pin mounted on the plug, offset from center. Used exclusively in Denmark, Greenland, and the Faroe Islands; EU accession has allowed Schuko (Type F) sockets in Danish homes since the early 1990s.

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.