The Railways Bill, published in 1993, established a complex structure for the rail industry. British Rail was to be broken up into over 100 separate companies, with most relationships between the successor companies established by contracts, some through regulatory mechanisms (such as the industry-wide network code and the multi-bilateral star model performance regime). Contracts for the use of railway facilities – track, stations and light maintenance depots – must be approved or directed by the Office of Rail & Road, although some facilities are exempt from this requirement. Contracts between the principal passenger train operators and the state are called franchise agreements, and were first established with the Office of Passenger Rail Franchising (OPRAF), then its successor the Strategic Rail Authority and now with the Secretary of State for Transport.