Hello, the source is the webpage mentioned in the source field of the change set. The web page contains the definition of the route by the operator on a Mapsmarker map and a downloadable gpx. We created the route upon request of the Belgian Compostela society, operator of the route. It's common that Compostela routes cross  borders (for example Via Scaldia, Via Brabantica, ... cross the Belgian/French border). That's how they are managed by the Compostela societies. Best regards, Daan