  The vector map layers data, provided there, originated from Gazetteer of Planetary Nomenclature
of International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN),
which published on USGS site: http://planetarynames.wr.usgs.gov. The MARS_nomenclature.zip was 
used from the site, which contains shape-file representation.
  The datum presented here in form of .VML-files (stands Vector Map Layer), which is
proprietary compressed format of author of the datum.
  Additionally the datum contains data for both Polar Regions of Mars re-projected to Polar 
Stereographic projection. Areas of this re-projecting coincide with respectives areas for
raster elevation data of MOLA instrument of MGS mission for respective Polar Regions.

See site of author: www.runspect.com for more details.
Copyright (c) 2011-2016 Yuri Feldman

