[JamesK]

Towards 2015 Strategic plan also states

"Criteria have been established for access into and retention of Category status to ensure that all involved make best endeavours to present a racing class that can capture the support of competitors, entrants, sponsors and spectators."

This statement is then followed by a pyramid graph ( I cant paste) showing the path to championship status, Starts with Clubmans to Sanctioned to Championship status.

This same document states,

For MotorSport NZ to consider status for a first or subsequent Championship the class must have been able to demonstrate the ability to have at least 15 vehicles contesting 75% of the previous seasons scheduled rounds of the series.

No "shall" here, only a "must" and a "previous"