Polygon for each Topo50 map sheet holding extents of each sheet, it's sheet code, name, edition, and revision statement. This is the same information that is printed on each Topo50 map
Data Dictionary for linz_map_sheet: http://apps.linz.govt.nz/topo-data-dictionary/index.aspx?page=class-linz_map_sheet
Although captured and 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
LINZ and our predecessors have been responsible for national topographic mapping in New Zealand for more than a hundred years.
The first digital data for the NZ Offshore Islands at 1:25,000 and 1:50,000 was created in the late 80's and early 90's by scanning the maps that existed at the time (the NZMS 272 series).
The raw data was created by photogrammetrists who from 1974 to 1997 mapped the islands from overlapping pairs of aerial photographs. Cartographers then took the data and added symbols and text, and created the colour separations needed to produce the printed maps.
New imagery of Snares is not currently (2011) available, however the data and maps has been converted to AKTM2000 Projection, and a map released in the 'Topo50' format.