# The Railways (Interoperability) Regulations 2011, Paragraph 2: Description of the subsystems


For each subsystem or part of a subsystem, the list of constituents and aspects relating to interoperability is proposed by the Secretary of State at the time of drawing up the relevant draft NTSN. Without prejudging the choice of aspects and constituents relating to interoperability or the order in which they will be made subject to NTSNs, the subsystems include the following—

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Source: https://www.legislation.gov.uk/uksi/2011/3066/schedule/3/paragraph/2 (the official version)
Page: https://openlegislation.uk/railways-interoperability-regulations-2011/schedule-3/paragraph-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.