Cross-border sections

Cross-border sections are the lines running from the last operating point (railway station, marshalling yard, changeover point) in Switzerland to the first operating point in the neighbouring country. It is particularly important that these sections are interoperable so that trains can run internationally. Switzerland's cross-border sections are listed in Annex 2 to the Rail Network Access Ordinance (RailNAO).

https://www.bav.admin.ch/content/bav/en/home/modes-of-transport/railways/informations-for-professionals/interoperability/cross-border-sections.html