NZ-WKO meaning in Regional ?

Waikato ( or ) is a local government region of the upper North Island of New Zealand. It covers the Waikato District, Waipa District, Matamata-Piako District, South Waikato District and Hamilton City, as well as Hauraki, Coromandel Peninsula, the northern King Country, much of the Taupō District, and parts of Rotorua District. It is governed by the Waikato Regional Council.

The region stretches from Coromandel Peninsula in the north, to the north-eastern slopes of Mount Ruapehu in the south, and spans the North Island from the west coast, through the Waikato and Hauraki to Coromandel Peninsula on the east coast. Broadly, the extent of the region is the Waikato River catchment. Other major catchments are those of the Waihou, Piako, Awakino and Mokau rivers. The region is bounded by Auckland on the north, Bay of Plenty on the east, Hawke's Bay on the south-east, and Manawatū-Whanganui and Taranaki on the south. Waikato Region is the fourth largest region in the country in area and population: It has an area of 25,000 km2 (9,700 sq mi) and a population of 506,000 (June 2021).

The region encompasses all or part of eleven territorial authorities, the most of any region of New Zealand. It is centred on the Waikato which consists of Waikato District, Matamata-Piako District, Waipa District, South Waikato District and Hamilton City. In descending order of land area the eleven territorial authorities are Taupō District (part), Waikato District, Waitomo District (part), Thames-Coromandel District, Ōtorohanga District, South Waikato District, Matamata-Piako District, Waipa District, Hauraki District, Rotorua District (part), and Hamilton City.

The name for the region is taken from the Waikato River; waikato is a Māori word traditionally translated as "flowing water" (specifically, wai = "water" and kato = "the pull of the river current in the sea").

When Waikato is used in spoken language it takes the definite article: the Waikato. But this usually refers to a smaller region than the Waikato local government region. Two definitions that would meet with wide acceptance are those of the Waikato rugby football union and of Hamilton Waikato tourism. The former takes in the local government areas of Hamilton City, the southern part of Waikato district, Waipa district, most of Matamata-Piako district and the South Waikato district. Hamilton Waikato tourism takes in additionally the northern part of Waikato district (Tuakau and other centres), the northern King Country (Waitomo and Ōtorohanga districts), and the Te Aroha district.

The parts of Waikato region beyond these limits are usually identified as Thames Valley and/or Hauraki/Coromandel (for the north-eastern part of Waikato region) and Taupō, on the Volcanic or Central Plateau (for the south-eastern part of the region).