To digitize polygons with a shared/common boundary in Didger:
- Digitize the first polygon.
- Outline the next area as a polyline (skipping the common border with the polygon).
- Select both the polygon and the polyline.
- Click Draw | New Boundaries | Polyline to Polygon with Shared Border (this command is in Tools rather than Draw in Didger 4).
Updated July 16, 2018