README updated

README.md

@@ -10,7 +10,6 @@ Download the two "large split polygons" shapefiles in WGS84 projection from:
 * http://openstreetmapdata.com/data/land-polygons
 * http://openstreetmapdata.com/data/water-polygons
 
-
 Shapefiles used in this application are derived from OSM data, © OpenStreetMap contributors.
 
 Create a `data` subdirectory in the directory with the jar file.
@@ -31,6 +30,22 @@ JAI library creates an AWT window. Run in headless mode:
 
 Test.
 
+## Validating Country of Origin ##
+
+Download two distinct shapefiles with country borders: 
+
+* http://thematicmapping.org/downloads/world_borders.php (TM_WORLD_BORDERS-0.3)
+* http://gadm.org/version2 (six dissolved layers)
+
+Unpack the zip archives and drop the data into the `data/` folder. The application will load
+`TM_WORLD_BORDERS-0.3.shp` and `gadm28_adm0.shp` (the top-admin-level shapefile) and 
+`gadm28_adm1.shp` (the 2nd-level admin regions shapefile).
+
+The `TM_WORLD_BORDERS` data is used for initial matching. Any mismatch will then be looked up in the
+very detailed `GADM0` and `GADM1` layers.
+
+
+
 ## Features ##
 
 * Accepts CSV as input, produces CSV output