With the 2013 revision of the Railways Ordinance (RailD), Switzerland amended its regulations governing standard-gauge railways to comply with EU requirements. According to European Directive 2008/57/EC, individual states must lay down binding notified national technical rules (NNTR) if their national regulations do not comply with the corresponding technical specifications for interoperability (TSl). The NNTR must be published and made availabte to all infrastructure managers and railway undertakings, vehicle keepers and conformity assessment bodies. Applicants are required to prove that their subsystem complies with the TSI and their NNTR.
NNTR are national requirements that differ from or supplement a TSI.