This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Swiss Signal . en Diagrams of railway signals in Switzerland own based on bav admin ch html lang de Schweizerische Eisenbahnen Schweizerische Fahrdienstvorschriften FDV published by Bundesamt fr Verkehr Bern regulation Signale chapters and Bundesamt fr Verkehr BAV Schweizerische Eisenbahnen redrawn or copied by Rebel