Shapefile dBase Data (naturalearthdata.com)

Question

I'm researching using natural earth for a software project, so I pulled down a sample data file and had a peek into its dBase file, namely ne_50m_admin_0_countries.dbf

Here is a sample row from said file:

ScaleRank =    1
LabelRank =    1
FeatureCla = Admin-0 countries
SOVEREIGNT = South Africa
SOV_A3 = ZAF
ADM0_DIF = 0.00
LEVEL = 2.00
TYPE = Sovereign country
ADMIN = South Africa
ADM0_A3 = ZAF
GEOU_DIF = 0.00
GEOUNIT = South Africa
GU_A3 = ZAF
SU_DIF = 0.00
SUBUNIT = South Africa
SU_A3 = ZAF
NAME = South Africa
ABBREV = S.Af.
POSTAL = ZA
NAME_FORMA = Republic of South Africa
TERR_ =
NAME_SORT = South Africa
MAP_COLOR =  2.00
POP_EST =   49052489.00
GDP_MD_EST =   491000.00
FIPS_10_ =   0.00
ISO_A2 = ZA
ISO_A3 = ZAF
ISO_N3 = 710.00

Now, what the heck is all of this stuff? I can guess what fields like "SOVEREIGNT" and "NAME" are, but what the heck is "ISO_A3", or "MAP_COLOR," or "ScaleRank"?

I tried to look for documentation in various places both on naturalearthdata.com and in other places, but I can't seem to find any. How exactly am I supposed to go about making sense of all those fields?

Answer 1

ISO stuff A2, A3, N3 are all associated with ISO-3166 global country codes and such.. Take a look at

http://www.unc.edu/~rowlett/units/codes/country.htm

Not sure of map_color or scale rank though.

Answer 2

the dbf file that came with shape file stores attribute of each of feature (a polygon, a line, a point etc). And it is totally upto person who created the shape file. So if you cannot guess what it is, you have to ask guys who created it.

I went to the website, and i guess you got this data Admin 0 – Countries. If what's written down there is not enough, you have to ask those guys there, as the data wont describe them. Sometimes shape file is accompanied with xml file which document what the data is, but for this particular data i saw only shp (defines polygons) dbf (attributes of each polygon) prj (map projection being used) and shx (i dont know what it is... indexing?).