¿Qué equipo descendió de la liga al final de la temporada 1991?
El Waterside Karori descendió al final de la temporada 1990, para ser sustituido por el ganador de una serie de eliminatorias entre equipos de las ligas norte, central y sur (Mount Albert-Ponsonby, Nelson United y Burndale United respectivamente). El Nelson United ganó la serie para conseguir el ascenso, pero existe cierta controversia sobre su participación en las eliminatorias, ya que sólo había quedado segundo en la liga regional central, que ganó el Petone.

El Gisborne City descendió al final de la temporada 1991
El Gisborne City descendió al final de la temporada de 1991.
Which team was relegated from the league at the conclusion of the 1991 Season?
Waterside Karori were relegated at the end of the 1990 season, to be replaced by the winner of a play-off series between teams from the northern, central, and southern leagues (Mount Albert-Ponsonby, Nelson United, and Burndale United respectively). Nelson United won the series to gain promotion, but there is some controversy about their participation in the play-offs as they had only finished second in the central regional league, which was won by Petone.[1]  

Gisborne City were relegated at the end of the 1991 season
Gisborne City were relegated at the end of the 1991 season.