A deliberately formed route of a lesser quality than a road
Data Dictionary for track_cl: http://apps.linz.govt.nz/topo-data-dictionary/index.aspx?page=class-track_cl
This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for New Zealand and it's offshore dependancies, at 1:50,000.
For some small islands the printed map scale is 1:25,000. Although presented at 1:25,000 this layer, for all intents and purposes, forms part of the Topo50 map series.
Further information on Topo50:
http://www.linz.govt.nz/topography/topo-maps/topo50