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documentation/frontend/components/maps/README.md

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+# Map features
+
+See component-specific docs at [CoordinateSelectionMap](./CoordinateSelectionMap.md) and [LocalityMap](./LocalityMap.md)
+
+The map features use the React Leaflet package and OpenStreetMap.
+
+### Dev notes
+
+- OSM Tile Usage Policy!
+
+  > for production: Tile Usage Policy https://operations.osmfoundation.org/policies/tiles/ of OpenStreetMap if you’re going to use the tiles in production.
+
+  > OpenStreetMap data is free for everyone to use. Our tile servers are not.
+  > Because OpenStreetMap data is free, many other organisations provide map tiles made from OSM data. If your project doesn’t meet our requirements, you can get OSM-derived map tiles elsewhere.
+
+- Make sure the map container has a defined height, for example by setting it in CSS: #map { height: 180px; }